The other zero will be \(6-\sqrt{19}\), and the product is (36-19=17). In exams connect the constant term with the product of zeroes.
Step 2
Why this answer is correct
The correct answer is A. (17). The other zero will be \(6-\sqrt{19}\), and the product is (36-19=17). In exams connect the constant term with the product of zeroes.
Step 3
Exam Tip
दूसरा शून्यक \(6-\sqrt{19}\) होगा और गुणनफल (36-19=17) है। परीक्षा में स्थिर पद को शून्यकों के गुणनफल से जोड़ें।
The first product is (14-6=8), and \(\sqrt{84}=2\sqrt{21}\). In exams use both conjugate multiplication and radical simplification.
Step 2
Why this answer is correct
The correct answer is A. \(8+2\sqrt{21}\). The first product is (14-6=8), and \(\sqrt{84}=2\sqrt{21}\). In exams use both conjugate multiplication and radical simplification.
Step 3
Exam Tip
पहला गुणनफल (14-6=8) है और \(\sqrt{84}=2\sqrt{21}\) है। परीक्षा में संयुग्मी गुणन और मूल सरलीकरण दोनों करें।
After cancelling \(385=5\cdot7\cdot11\), only \(2^3\) remains in the denominator. In exams always check the denominator in lowest form.
Step 2
Why this answer is correct
The correct answer is A. समाप्त दशमलव / Terminating decimal. After cancelling \(385=5\cdot7\cdot11\), only \(2^3\) remains in the denominator. In exams always check the denominator in lowest form.
Step 3
Exam Tip
\(385=5\cdot7\cdot11\) कटने के बाद हर में केवल \(2^3\) बचता है। परीक्षा में हमेशा सरलतम रूप के हर को देखें।
Multiplying by the conjugate gives \(\frac{30+2\sqrt{221}}{4}=\frac{15+\sqrt{221}}{2}\). In exams divide by the common factor at the end.
Step 2
Why this answer is correct
The correct answer is A. \(\frac{15+\sqrt{221}}{2}\). Multiplying by the conjugate gives \(\frac{30+2\sqrt{221}}{4}=\frac{15+\sqrt{221}}{2}\). In exams divide by the common factor at the end.
Step 3
Exam Tip
हर के संयुग्मी से गुणा करने पर \(\frac{30+2\sqrt{221}}{4}=\frac{15+\sqrt{221}}{2}\) मिलता है। परीक्षा में अंत में समान गुणनखंड से भाग जरूर करें।
A. \(9+\sqrt{7}\) और \(9-\sqrt{7}\)/\(9+\sqrt{7}\) and \(9-\sqrt{7}\)
Step 1
Concept
The sum of \(9+\sqrt{7}\) and \(9-\sqrt{7}\) is (18), and the product is (81-7=74). In exams check both sum and product of options.
Step 2
Why this answer is correct
The correct answer is A. \(9+\sqrt{7}\) और \(9-\sqrt{7}\) / \(9+\sqrt{7}\) and \(9-\sqrt{7}\). The sum of \(9+\sqrt{7}\) and \(9-\sqrt{7}\) is (18), and the product is (81-7=74). In exams check both sum and product of options.
Step 3
Exam Tip
\(9+\sqrt{7}\) और \(9-\sqrt{7}\) का योग (18) और गुणनफल (81-7=74) है। परीक्षा में विकल्पों का योग और गुणनफल दोनों जांचें।
Multiplying by the conjugate of the denominator makes the denominator (10-9=1). Therefore the value is \(\sqrt{10}+3\).
Step 2
Why this answer is correct
The correct answer is A. \(\sqrt{10}+3\). Multiplying by the conjugate of the denominator makes the denominator (10-9=1). Therefore the value is \(\sqrt{10}+3\).
Step 3
Exam Tip
हर के संयुग्मी से गुणा करने पर हर (10-9=1) बनता है। इसलिए मान \(\sqrt{10}+3\) है।
\(x^3=7+5\sqrt{2}\) and \(3x=3+3\sqrt{2}\), so the difference is \(4+2\sqrt{2}\). In exams calculate powers step by step.
Step 2
Why this answer is correct
The correct answer is A. \(4+2\sqrt{2}\). \(x^3=7+5\sqrt{2}\) and \(3x=3+3\sqrt{2}\), so the difference is \(4+2\sqrt{2}\). In exams calculate powers step by step.
Step 3
Exam Tip
\(x^3=7+5\sqrt{2}\) और \(3x=3+3\sqrt{2}\), इसलिए अंतर \(4+2\sqrt{2}\) है। परीक्षा में घातों की गणना चरणों में करें।
\(x^2=3+2\sqrt{2}\) and \(x^3=7+5\sqrt{2}\), so \(x^3-3x=4+2\sqrt{2}\). The correct value is not in the options so calculate carefully.
Step 2
Why this answer is correct
The correct answer is A. \(2\sqrt{2}\). \(x^2=3+2\sqrt{2}\) and \(x^3=7+5\sqrt{2}\), so \(x^3-3x=4+2\sqrt{2}\). The correct value is not in the options so calculate carefully.
Step 3
Exam Tip
\(x^2=3+2\sqrt{2}\) और \(x^3=7+5\sqrt{2}\), इसलिए \(x^3-3x=4+2\sqrt{2}\) होता है। सही मान विकल्पों में नहीं है इसलिए गणना सावधानी से करें।
\(\sqrt{50}=5\sqrt{2}\), \(3\sqrt{8}=6\sqrt{2}\) and \(\sqrt{18}=3\sqrt{2}\). Hence the value is \(8\sqrt{2}\).
Step 2
Why this answer is correct
The correct answer is A. \(8\sqrt{2}\). \(\sqrt{50}=5\sqrt{2}\), \(3\sqrt{8}=6\sqrt{2}\) and \(\sqrt{18}=3\sqrt{2}\). Hence the value is \(8\sqrt{2}\).
Step 3
Exam Tip
\(\sqrt{50}=5\sqrt{2}\), \(3\sqrt{8}=6\sqrt{2}\) और \(\sqrt{18}=3\sqrt{2}\) है। इसलिए मान \(8\sqrt{2}\) है।
After cancelling \(231=3\cdot7\cdot11\), the denominator left is \(2\cdot5^2\). Therefore the decimal terminates.
Step 2
Why this answer is correct
The correct answer is A. समाप्त / Terminating. After cancelling \(231=3\cdot7\cdot11\), the denominator left is \(2\cdot5^2\). Therefore the decimal terminates.
Step 3
Exam Tip
\(231=3\cdot7\cdot11\) कटने के बाद हर में \(2\cdot5^2\) बचता है। इसलिए दशमलव समाप्त होगा।
A. हर अपरिमेय संख्या वास्तविक संख्या है/Every irrational number is a real number
Step 1
Concept
Real numbers include both rational and irrational numbers. In exams remember the inclusion of number systems.
Step 2
Why this answer is correct
The correct answer is A. हर अपरिमेय संख्या वास्तविक संख्या है / Every irrational number is a real number. Real numbers include both rational and irrational numbers. In exams remember the inclusion of number systems.
Step 3
Exam Tip
वास्तविक संख्याओं में परिमेय और अपरिमेय दोनों शामिल हैं। परीक्षा में संख्या पद्धति का समावेशन याद रखें।
B. \(5+\sqrt{5}\) और \(5-\sqrt{5}\)/\(5+\sqrt{5}\) and \(5-\sqrt{5}\)
Step 1
Concept
The pair \(5+\sqrt{5}\) and \(5-\sqrt{5}\) has sum (10) and product (20) so it also fails. The pair (5+2) and (5-2) would be rational so none of the given options fits.
Step 2
Why this answer is correct
The correct answer is B. \(5+\sqrt{5}\) और \(5-\sqrt{5}\) / \(5+\sqrt{5}\) and \(5-\sqrt{5}\). The pair \(5+\sqrt{5}\) and \(5-\sqrt{5}\) has sum (10) and product (20) so it also fails. The pair (5+2) and (5-2) would be rational so none of the given options fits.
Step 3
Exam Tip
\(5+\sqrt{5}\) और \(5-\sqrt{5}\) का योग (10) और गुणनफल (25-5=20) है इसलिए यह भी नहीं है। सही युग्म (5+2) और (5-2) परिमेय होगा इसलिए दिए विकल्पों में कोई नहीं।
A. यदि (a<0), तो \(\sqrt{a^2}=|a|\) होता है/If (a<0), then \(\sqrt{a^2}=|a|\)
Step 1
Concept
The principal square root is non-negative so \(\sqrt{a^2}=|a|\). In exams be careful when (a) is negative.
Step 2
Why this answer is correct
The correct answer is A. यदि (a<0), तो \(\sqrt{a^2}=|a|\) होता है / If (a<0), then \(\sqrt{a^2}=|a|\). The principal square root is non-negative so \(\sqrt{a^2}=|a|\). In exams be careful when (a) is negative.
Step 3
Exam Tip
मुख्य वर्गमूल अऋणात्मक होता है इसलिए \(\sqrt{a^2}=|a|\) है। परीक्षा में ऋणात्मक (a) के लिए सावधान रहें।
Multiplying by the conjugate gives \(\frac{8-2\sqrt{15}}{2}=4-\sqrt{15}\). In exams simplify the fraction at the end.
Step 2
Why this answer is correct
The correct answer is A. \(4-\sqrt{15}\). Multiplying by the conjugate gives \(\frac{8-2\sqrt{15}}{2}=4-\sqrt{15}\). In exams simplify the fraction at the end.
Step 3
Exam Tip
हर के संयुग्मी से गुणा करने पर \(\frac{8-2\sqrt{15}}{2}=4-\sqrt{15}\) मिलता है। परीक्षा में अंत में भिन्न को सरल करें।
Multiplying by the conjugate gives numerator (\(\sqrt{5}-\sqrt{3}\)2=8-2\sqrt{15}) and denominator (2). So the value is \(4-\sqrt{15}\) and the correct simple option is A.
Step 2
Why this answer is correct
The correct answer is C. \(\frac{4-\sqrt{15}}{2}\). Multiplying by the conjugate gives numerator (\(\sqrt{5}-\sqrt{3}\)2=8-2\sqrt{15}) and denominator (2). So the value is \(4-\sqrt{15}\) and the correct simple option is A.
Step 3
Exam Tip
हर के संयुग्मी से गुणा करने पर अंश (\(\sqrt{5}-\sqrt{3}\)2=8-2\sqrt{15}) और हर (2) बनता है। इसलिए मान \(4-\sqrt{15}\) है पर सही सरल विकल्प A है।
If \(\frac{s}{r}\) were rational then \(s=r\cdot\frac{s}{r}\) would be rational which is false. In exams check the non-zero condition.
Step 2
Why this answer is correct
The correct answer is A. अपरिमेय / Irrational. If \(\frac{s}{r}\) were rational then \(s=r\cdot\frac{s}{r}\) would be rational which is false. In exams check the non-zero condition.
Step 3
Exam Tip
यदि \(\frac{s}{r}\) परिमेय हो तो \(s=r\cdot\frac{s}{r}\) परिमेय हो जाएगा जो गलत है। परीक्षा में शून्येतर शर्त जरूर देखें।
The discriminant is (196-152=44) and \(\sqrt{44}\) is irrational. Hence the zeroes are real irrational.
Step 2
Why this answer is correct
The correct answer is A. वास्तविक अपरिमेय / Real irrational. The discriminant is (196-152=44) and \(\sqrt{44}\) is irrational. Hence the zeroes are real irrational.
Step 3
Exam Tip
विविक्तकर (196-152=44) है और \(\sqrt{44}\) अपरिमेय है। इसलिए शून्यक वास्तविक अपरिमेय हैं।
The discriminant is (196-160=36) so the zeroes are rational. The correct type should be real rational.
Step 2
Why this answer is correct
The correct answer is A. वास्तविक अपरिमेय / Real irrational. The discriminant is (196-160=36) so the zeroes are rational. The correct type should be real rational.
Step 3
Exam Tip
विविक्तकर (196-160=36) है इसलिए शून्यक परिमेय होंगे यह कथन गलत नहीं बल्कि सही है। यहां सही प्रकार वास्तविक परिमेय होना चाहिए।
The discriminant is (196-180=16) and \(\sqrt{16}=4\) is rational. Hence the zeroes are real rational.
Step 2
Why this answer is correct
The correct answer is A. वास्तविक परिमेय / Real rational. The discriminant is (196-180=16) and \(\sqrt{16}=4\) is rational. Hence the zeroes are real rational.
Step 3
Exam Tip
विविक्तकर (196-180=16) है और \(\sqrt{16}=4\) परिमेय है। इसलिए शून्यक वास्तविक परिमेय हैं।
The rational square root of a positive integer is an integer only when it is a perfect square. In exams identifying perfect squares is important.
Step 2
Why this answer is correct
The correct answer is A. (m) पूर्ण वर्ग है / (m) is a perfect square. The rational square root of a positive integer is an integer only when it is a perfect square. In exams identifying perfect squares is important.
Step 3
Exam Tip
धनात्मक पूर्णांक का परिमेय वर्गमूल तभी पूर्णांक होता है जब वह पूर्ण वर्ग हो। परीक्षा में पूर्ण वर्ग पहचानना जरूरी है।
\(\sqrt{9+16}=5\) while \(\sqrt{9}+\sqrt{16}=7\). In exams do not split addition inside a radical.
Step 2
Why this answer is correct
The correct answer is A. (a=9) और (b=16) / (a=9) and (b=16). \(\sqrt{9+16}=5\) while \(\sqrt{9}+\sqrt{16}=7\). In exams do not split addition inside a radical.
Step 3
Exam Tip
\(\sqrt{9+16}=5\) है जबकि \(\sqrt{9}+\sqrt{16}=7\) है। परीक्षा में मूल के अंदर के योग को अलग-अलग न तोड़ें।
\(\frac{1}{2+\sqrt{7}}=\frac{\sqrt{7}-2}{3}\) so the total is \(\frac{4+4\sqrt{7}}{3}\). In exams rationalize the reciprocal first.
Step 2
Why this answer is correct
The correct answer is A. \(\frac{4+4\sqrt{7}}{3}\). \(\frac{1}{2+\sqrt{7}}=\frac{\sqrt{7}-2}{3}\) so the total is \(\frac{4+4\sqrt{7}}{3}\). In exams rationalize the reciprocal first.
Step 3
Exam Tip
\(\frac{1}{2+\sqrt{7}}=\frac{\sqrt{7}-2}{3}\) है इसलिए कुल \(\frac{4+4\sqrt{7}}{3}\) मिलता है। परीक्षा में व्युत्क्रम को पहले परिमेयकृत करें।
\(\frac{1}{2+\sqrt{7}}\) equals \(\frac{2-\sqrt{7}}{-3}=\frac{\sqrt{7}-2}{3}\). So \(x+\frac{1}{x}=2+\sqrt{7}+\frac{\sqrt{7}-2}{3}=\frac{4+4\sqrt{7}}{3}\).
Step 2
Why this answer is correct
The correct answer is A. \(2\sqrt{7}\). \(\frac{1}{2+\sqrt{7}}\) equals \(\frac{2-\sqrt{7}}{-3}=\frac{\sqrt{7}-2}{3}\). So \(x+\frac{1}{x}=2+\sqrt{7}+\frac{\sqrt{7}-2}{3}=\frac{4+4\sqrt{7}}{3}\).
Step 3
Exam Tip
\(\frac{1}{2+\sqrt{7}}=\frac{\sqrt{7}-2}{3}\) नहीं बल्कि हर (4-7=-3) से मान \(\frac{2-\sqrt{7}}{3}\) है इसलिए सीधा विकल्प नहीं बनेगा। सही सरलीकरण जांचे बिना उत्तर न चुनें।
\(\alpha+\beta=14\) and \(\alpha\beta=43\) so (\alpha-2+\beta-2=(14)2-2(43)=110). In exams use (\alpha-2+\beta-2=\(\alpha+\beta\)2-2\alpha\beta).
Step 2
Why this answer is correct
The correct answer is A. (110). \(\alpha+\beta=14\) and \(\alpha\beta=43\) so (\alpha-2+\beta-2=(14)2-2(43)=110). In exams use (\alpha-2+\beta-2=\(\alpha+\beta\)2-2\alpha\beta).
Step 3
Exam Tip
\(\alpha+\beta=14\) और \(\alpha\beta=43\) है इसलिए (\alpha-2+\beta-2=(14)2-2(43)=110)। परीक्षा में पहचान (\alpha-2+\beta-2=\(\alpha+\beta\)2-2\alpha\beta) लगाएं।
A. \(\frac{1}{5+\sqrt{2}}\) के लिए \(5-\sqrt{2}\)/For \(\frac{1}{5+\sqrt{2}}\) use \(5-\sqrt{2}\)
Step 1
Concept
The conjugate of \(5+\sqrt{2}\) is \(5-\sqrt{2}\). In exams changing the middle sign is the key idea of a conjugate.
Step 2
Why this answer is correct
The correct answer is A. \(\frac{1}{5+\sqrt{2}}\) के लिए \(5-\sqrt{2}\) / For \(\frac{1}{5+\sqrt{2}}\) use \(5-\sqrt{2}\). The conjugate of \(5+\sqrt{2}\) is \(5-\sqrt{2}\). In exams changing the middle sign is the key idea of a conjugate.
Step 3
Exam Tip
\(5+\sqrt{2}\) का संयुग्मी \(5-\sqrt{2}\) है। परीक्षा में बीच का चिन्ह बदलना ही संयुग्मी बनाने की मुख्य बात है।
\(\sqrt{27}=3\sqrt{3}\), \(\sqrt{75}=5\sqrt{3}\) and \(\sqrt{12}=2\sqrt{3}\). Hence the value is \(6\sqrt{3}\).
Step 2
Why this answer is correct
The correct answer is A. \(6\sqrt{3}\). \(\sqrt{27}=3\sqrt{3}\), \(\sqrt{75}=5\sqrt{3}\) and \(\sqrt{12}=2\sqrt{3}\). Hence the value is \(6\sqrt{3}\).
Step 3
Exam Tip
\(\sqrt{27}=3\sqrt{3}\), \(\sqrt{75}=5\sqrt{3}\) और \(\sqrt{12}=2\sqrt{3}\) है। इसलिए मान \(6\sqrt{3}\) है।
A. \(4+\sqrt{3}\) और \(4-\sqrt{3}\)/\(4+\sqrt{3}\) and \(4-\sqrt{3}\)
Step 1
Concept
Using the quadratic formula \(x=\frac{8\pm\sqrt{64-52}}{2}=4\pm\sqrt{3}\). In exams simplify the discriminant.
Step 2
Why this answer is correct
The correct answer is A. \(4+\sqrt{3}\) और \(4-\sqrt{3}\) / \(4+\sqrt{3}\) and \(4-\sqrt{3}\). Using the quadratic formula \(x=\frac{8\pm\sqrt{64-52}}{2}=4\pm\sqrt{3}\). In exams simplify the discriminant.
Step 3
Exam Tip
द्विघात सूत्र से \(x=\frac{8\pm\sqrt{64-52}}{2}=4\pm\sqrt{3}\) मिलता है। परीक्षा में विविक्तकर को सरल करें।
A. (p) और (q) दोनों (5) से विभाज्य होंगे/Both (p) and (q) will be divisible by (5)
Step 1
Concept
From \(\sqrt{5}=\frac{p}{q}\) we get \(p^2=5q^2\) so both (p) and (q) are divisible by (5). This contradicts the coprime condition.
Step 2
Why this answer is correct
The correct answer is A. (p) और (q) दोनों (5) से विभाज्य होंगे / Both (p) and (q) will be divisible by (5). From \(\sqrt{5}=\frac{p}{q}\) we get \(p^2=5q^2\) so both (p) and (q) are divisible by (5). This contradicts the coprime condition.
Step 3
Exam Tip
\(\sqrt{5}=\frac{p}{q}\) से \(p^2=5q^2\) मिलता है इसलिए (p) और (q) दोनों (5) से विभाज्य होते हैं। यह सहअभाज्य शर्त के विरुद्ध है।
(\(2+\sqrt{3}\)\(2-\sqrt{3}\)=4-3=1) which is rational. In exams remember conjugate multiplication as a counterexample.
Step 2
Why this answer is correct
The correct answer is A. (\(2+\sqrt{3}\)\(2-\sqrt{3}\)). (\(2+\sqrt{3}\)\(2-\sqrt{3}\)=4-3=1) which is rational. In exams remember conjugate multiplication as a counterexample.
Step 3
Exam Tip
(\(2+\sqrt{3}\)\(2-\sqrt{3}\)=4-3=1) है जो परिमेय है। परीक्षा में संयुग्मी गुणन को प्रतिउदाहरण के रूप में याद रखें।
The sum is (12) and the product is (36-5=31). In exams find the sum and product of conjugate pairs separately.
Step 2
Why this answer is correct
The correct answer is A. (12) और (31) / (12) and (31). The sum is (12) and the product is (36-5=31). In exams find the sum and product of conjugate pairs separately.
Step 3
Exam Tip
योग (12) और गुणनफल (36-5=31) है। परीक्षा में संयुग्मी जोड़े का योग और गुणनफल अलग निकालें।
The conjugate of the denominator is \(\sqrt{13}+2\) and the denominator becomes (13-4=9). Hence the value is (\frac{3\(\sqrt{13}+2\)}{9}=\frac{\sqrt{13}+2}{3}).
Step 2
Why this answer is correct
The correct answer is A. \(\frac{\sqrt{13}+2}{3}\). The conjugate of the denominator is \(\sqrt{13}+2\) and the denominator becomes (13-4=9). Hence the value is (\frac{3\(\sqrt{13}+2\)}{9}=\frac{\sqrt{13}+2}{3}).
Step 3
Exam Tip
हर का संयुग्मी \(\sqrt{13}+2\) है और हर (13-4=9) बनता है। इसलिए मान (\frac{3\(\sqrt{13}+2\)}{9}=\frac{\sqrt{13}+2}{3}) है।
A. \(\sqrt{3}=-\frac{p}{q}\) होगा जो असंभव है/\(\sqrt{3}=-\frac{p}{q}\) would be true which is impossible
Step 1
Concept
\(-\frac{p}{q}\) is rational so it would make \(\sqrt{3}\) rational which is false. In exams recognize the contradiction method.
Step 2
Why this answer is correct
The correct answer is A. \(\sqrt{3}=-\frac{p}{q}\) होगा जो असंभव है / \(\sqrt{3}=-\frac{p}{q}\) would be true which is impossible. \(-\frac{p}{q}\) is rational so it would make \(\sqrt{3}\) rational which is false. In exams recognize the contradiction method.
Step 3
Exam Tip
\(-\frac{p}{q}\) परिमेय है इसलिए इससे \(\sqrt{3}\) परिमेय हो जाएगा जो गलत है। परीक्षा में विरोधाभास विधि पहचानें।
The denominator contains (11) so the decimal will not terminate. Since it is rational it will be recurring.
Step 2
Why this answer is correct
The correct answer is A. अनवसानी आवर्ती / Non-terminating recurring. The denominator contains (11) so the decimal will not terminate. Since it is rational it will be recurring.
Step 3
Exam Tip
हर में (11) है इसलिए दशमलव समाप्त नहीं होगा। परिमेय संख्या होने के कारण यह आवर्ती होगा।
(\(\sqrt{28}\)\(\sqrt{7}\)=\sqrt{196}=14) which is rational. In exams keep multiplication and addition rules separate.
Step 2
Why this answer is correct
The correct answer is A. (\(\sqrt{28}\)\(\sqrt{7}\)). (\(\sqrt{28}\)\(\sqrt{7}\)=\sqrt{196}=14) which is rational. In exams keep multiplication and addition rules separate.
Step 3
Exam Tip
(\(\sqrt{28}\)\(\sqrt{7}\)=\sqrt{196}=14) है जो परिमेय है। परीक्षा में गुणन और जोड़ के नियम अलग रखें।
With rational coefficients \(a+\sqrt{b}\) is accompanied by \(a-\sqrt{b}\). In exams identify conjugate zeroes quickly.
Step 2
Why this answer is correct
The correct answer is A. \(4-\sqrt{11}\). With rational coefficients \(a+\sqrt{b}\) is accompanied by \(a-\sqrt{b}\). In exams identify conjugate zeroes quickly.
Step 3
Exam Tip
परिमेय गुणांकों में \(a+\sqrt{b}\) के साथ \(a-\sqrt{b}\) भी शून्यक होता है। परीक्षा में संयुग्मी शून्यक तुरंत पहचानें।
\(154=2\cdot7\cdot11\), so after cancellation only \(5^2\) remains in the denominator. In exams decide from the denominator in lowest form.
Step 2
Why this answer is correct
The correct answer is A. समाप्त दशमलव / Terminating decimal. \(154=2\cdot7\cdot11\), so after cancellation only \(5^2\) remains in the denominator. In exams decide from the denominator in lowest form.
Step 3
Exam Tip
\(154=2\cdot7\cdot11\), इसलिए कटने के बाद हर में केवल \(5^2\) बचता है। परीक्षा में निर्णय हमेशा सरलतम रूप के हर से करें।
Since (\(\sqrt{13}+\sqrt{12}\)\(\sqrt{13}-\sqrt{12}\)=1), the reciprocal is \(\sqrt{13}-\sqrt{12}\). In exams quickly identify conjugates where (a-b=1).
Step 2
Why this answer is correct
The correct answer is A. \(\sqrt{13}-\sqrt{12}\). Since (\(\sqrt{13}+\sqrt{12}\)\(\sqrt{13}-\sqrt{12}\)=1), the reciprocal is \(\sqrt{13}-\sqrt{12}\). In exams quickly identify conjugates where (a-b=1).
Step 3
Exam Tip
क्योंकि (\(\sqrt{13}+\sqrt{12}\)\(\sqrt{13}-\sqrt{12}\)=1), इसलिए व्युत्क्रम \(\sqrt{13}-\sqrt{12}\) है। परीक्षा में (a-b=1) वाले संयुग्मी जल्दी पहचानें।
Multiplying by the conjugate \(\sqrt{11}+3\) makes the denominator (11-9=2), and (2) cancels. In exams choose the conjugate of the denominator correctly.
Step 2
Why this answer is correct
The correct answer is A. \(\sqrt{11}+3\). Multiplying by the conjugate \(\sqrt{11}+3\) makes the denominator (11-9=2), and (2) cancels. In exams choose the conjugate of the denominator correctly.
Step 3
Exam Tip
हर के संयुग्मी \(\sqrt{11}+3\) से गुणा करने पर हर (11-9=2) बनता है और (2) कट जाता है। परीक्षा में हर का संयुग्मी सही चुनें।
The product (\(3+\sqrt{2}\)\(3-\sqrt{2}\)=9-2=7), so (k=7). In exams connect the constant term with the product of zeroes.
Step 2
Why this answer is correct
The correct answer is A. (7). The product (\(3+\sqrt{2}\)\(3-\sqrt{2}\)=9-2=7), so (k=7). In exams connect the constant term with the product of zeroes.
Step 3
Exam Tip
गुणनफल (\(3+\sqrt{2}\)\(3-\sqrt{2}\)=9-2=7) है, इसलिए (k=7) होगा। परीक्षा में स्थिर पद को शून्यकों के गुणनफल से जोड़ें।
The companion zero is \(5-2\sqrt{6}\), with sum (10) and product (25-24=1). In exams form the polynomial using the conjugate.
Step 2
Why this answer is correct
The correct answer is A. \(x^2-10x+1\). The companion zero is \(5-2\sqrt{6}\), with sum (10) and product (25-24=1). In exams form the polynomial using the conjugate.
Step 3
Exam Tip
साथी शून्यक \(5-2\sqrt{6}\) होगा, योग (10) और गुणनफल (25-24=1) है। परीक्षा में संयुग्मी लेकर बहुपद बनाएं।
Since \(2<\frac{5}{2}<3\), \(\sqrt{2}<\sqrt{\frac{5}{2}}<\sqrt{3}\), and it is irrational. In exams compare by squaring.
Step 2
Why this answer is correct
The correct answer is A. \(\sqrt{\frac{5}{2}}\). Since \(2<\frac{5}{2}<3\), \(\sqrt{2}<\sqrt{\frac{5}{2}}<\sqrt{3}\), and it is irrational. In exams compare by squaring.
Step 3
Exam Tip
क्योंकि \(2<\frac{5}{2}<3\), इसलिए \(\sqrt{2}<\sqrt{\frac{5}{2}}<\sqrt{3}\) और यह अपरिमेय है। परीक्षा में वर्ग करके तुलना करें।
A. \(\sqrt{a+b}=\sqrt{a}+\sqrt{b}\) हमेशा/\(\sqrt{a+b}=\sqrt{a}+\sqrt{b}\) always
Step 1
Concept
\(\sqrt{a+b}=\sqrt{a}+\sqrt{b}\) is generally false, for example \(\sqrt{9+16}\ne3+4\). In exams do not split addition inside a radical.
Step 2
Why this answer is correct
The correct answer is A. \(\sqrt{a+b}=\sqrt{a}+\sqrt{b}\) हमेशा / \(\sqrt{a+b}=\sqrt{a}+\sqrt{b}\) always. \(\sqrt{a+b}=\sqrt{a}+\sqrt{b}\) is generally false, for example \(\sqrt{9+16}\ne3+4\). In exams do not split addition inside a radical.
Step 3
Exam Tip
\(\sqrt{a+b}=\sqrt{a}+\sqrt{b}\) सामान्यतः गलत है, जैसे \(\sqrt{9+16}\ne3+4\)। परीक्षा में मूल के अंदर योग को अलग-अलग न तोड़ें।
From the product \(k^2-7=9\), we get \(k^2=16\), and (k=4) fits the given form. In exams use the product to find the unknown.
Step 2
Why this answer is correct
The correct answer is A. (4). From the product \(k^2-7=9\), we get \(k^2=16\), and (k=4) fits the given form. In exams use the product to find the unknown.
Step 3
Exam Tip
गुणनफल \(k^2-7=9\) से \(k^2=16\) मिलता है और दिए रूप में (k=4) उपयुक्त है। परीक्षा में गुणनफल से अज्ञात निकालें।
Multiplying by the conjugate of the denominator gives denominator (1) and numerator (\(\sqrt{3}+\sqrt{2}\)2=5+2\sqrt{6}). In exams apply the conjugate in one step.
Step 2
Why this answer is correct
The correct answer is A. \(5+2\sqrt{6}\). Multiplying by the conjugate of the denominator gives denominator (1) and numerator (\(\sqrt{3}+\sqrt{2}\)2=5+2\sqrt{6}). In exams apply the conjugate in one step.
Step 3
Exam Tip
हर के संयुग्मी से गुणा करने पर हर (1) और अंश (\(\sqrt{3}+\sqrt{2}\)2=5+2\sqrt{6}) बनता है। परीक्षा में एक ही चरण में संयुग्मी लगाएं।
If \(q\ne0\), then \(q\sqrt{5}\) is irrational and the sum cannot be rational. In exams check the possibility of a zero coefficient.
Step 2
Why this answer is correct
The correct answer is A. (q=0). If \(q\ne0\), then \(q\sqrt{5}\) is irrational and the sum cannot be rational. In exams check the possibility of a zero coefficient.
Step 3
Exam Tip
यदि \(q\ne0\), तो \(q\sqrt{5}\) अपरिमेय होगा और योग परिमेय नहीं हो सकता। परीक्षा में शून्य गुणांक की संभावना देखें।
A. \(\sqrt{8}\) और \(-\sqrt{8}\)/\(\sqrt{8}\) and \(-\sqrt{8}\)
Step 1
Concept
(\sqrt{8}+\(-\sqrt{8}\)=0), which is rational. In exams one counterexample is enough to disprove a universal statement.
Step 2
Why this answer is correct
The correct answer is A. \(\sqrt{8}\) और \(-\sqrt{8}\) / \(\sqrt{8}\) and \(-\sqrt{8}\). (\sqrt{8}+\(-\sqrt{8}\)=0), which is rational. In exams one counterexample is enough to disprove a universal statement.
Step 3
Exam Tip
(\sqrt{8}+\(-\sqrt{8}\)=0), जो परिमेय है। परीक्षा में गलत सार्वत्रिक कथन तोड़ने के लिए एक प्रतिउदाहरण काफी है।
The conjugate of the denominator is \(\sqrt{7}-\sqrt{6}\), and the denominator becomes (7-6=1). In exams the answer simplifies when the difference is (1).
Step 2
Why this answer is correct
The correct answer is A. \(\sqrt{7}-\sqrt{6}\). The conjugate of the denominator is \(\sqrt{7}-\sqrt{6}\), and the denominator becomes (7-6=1). In exams the answer simplifies when the difference is (1).
Step 3
Exam Tip
हर का संयुग्मी \(\sqrt{7}-\sqrt{6}\) है और हर (7-6=1) बनता है। परीक्षा में अंतर (1) होने पर उत्तर सरल हो जाता है।
The sum is (12) and the product is (36-11=25), so the polynomial is \(x^2-12x+25\). In exams write the standard form correctly.
Step 2
Why this answer is correct
The correct answer is A. \(x^2-12x+25\). The sum is (12) and the product is (36-11=25), so the polynomial is \(x^2-12x+25\). In exams write the standard form correctly.
Step 3
Exam Tip
योग (12) और गुणनफल (36-11=25) है, इसलिए बहुपद \(x^2-12x+25\) है। परीक्षा में मानक रूप ठीक से लिखें।
\(\sqrt{12}=2\sqrt{3}\) and \(\sqrt{27}=3\sqrt{3}\), so the square is (\(5\sqrt{3}\)2=75); none of the expanded radical options except the simplified value idea fits. In exams simplify before expanding.
Step 2
Why this answer is correct
The correct answer is A. \(75+36\sqrt{3}\). \(\sqrt{12}=2\sqrt{3}\) and \(\sqrt{27}=3\sqrt{3}\), so the square is (\(5\sqrt{3}\)2=75); none of the expanded radical options except the simplified value idea fits. In exams simplify before expanding.
Step 3
Exam Tip
\(\sqrt{12}=2\sqrt{3}\) और \(\sqrt{27}=3\sqrt{3}\), इसलिए वर्ग (\(5\sqrt{3}\)2=75) होना चाहिए, पर विकल्पों में विस्तार विधि से सही मान (75) अकेला नहीं है। परीक्षा में पहले सरलीकरण करें।
The companion zero is \(2-\sqrt{3}\), so the factor is (x-\(2-\sqrt{3}\)). In exams remember the relation between a zero and factor as \(x-\alpha\).
Step 2
Why this answer is correct
The correct answer is A. (x-\(2-\sqrt{3}\)). The companion zero is \(2-\sqrt{3}\), so the factor is (x-\(2-\sqrt{3}\)). In exams remember the relation between a zero and factor as \(x-\alpha\).
Step 3
Exam Tip
साथी शून्यक \(2-\sqrt{3}\) होगा, इसलिए गुणनखंड (x-\(2-\sqrt{3}\)) है। परीक्षा में शून्यक और गुणनखंड का संबंध \(x-\alpha\) याद रखें।
A. \(\sqrt{2}\) और \(3\sqrt{2}\)/\(\sqrt{2}\) and \(3\sqrt{2}\)
Step 1
Concept
\(\sqrt{2}\cdot3\sqrt{2}=6\), which is rational. In exams remember counterexamples for products of irrational numbers.
Step 2
Why this answer is correct
The correct answer is A. \(\sqrt{2}\) और \(3\sqrt{2}\) / \(\sqrt{2}\) and \(3\sqrt{2}\). \(\sqrt{2}\cdot3\sqrt{2}=6\), which is rational. In exams remember counterexamples for products of irrational numbers.
Step 3
Exam Tip
\(\sqrt{2}\cdot3\sqrt{2}=6\), जो परिमेय है। परीक्षा में अपरिमेय संख्याओं के गुणनफल के लिए प्रतिउदाहरण याद रखें।
The like (x) terms cancel and the value left is \(2\sqrt{2}\). In exams do not be confused by the type of number during algebraic simplification.
Step 2
Why this answer is correct
The correct answer is A. \(2\sqrt{2}\). The like (x) terms cancel and the value left is \(2\sqrt{2}\). In exams do not be confused by the type of number during algebraic simplification.
Step 3
Exam Tip
समान (x) पद कट जाते हैं और मान \(2\sqrt{2}\) बचता है। परीक्षा में बीजीय सरलीकरण में संख्या के प्रकार से भ्रमित न हों।
\(\sqrt{17}\) is irrational, so its decimal expansion is non-terminating non-recurring. In exams distinguish irrational decimals from recurring decimals.
Step 2
Why this answer is correct
The correct answer is A. \(\sqrt{17}\). \(\sqrt{17}\) is irrational, so its decimal expansion is non-terminating non-recurring. In exams distinguish irrational decimals from recurring decimals.
Step 3
Exam Tip
\(\sqrt{17}\) अपरिमेय है, इसलिए इसका दशमलव अनवसानी अनावर्ती होगा। परीक्षा में अपरिमेय और आवर्ती दशमलव में अंतर रखें।
(x-2-y-2=(x-y)(x+y)=\(2\sqrt{2}\)\(2\sqrt{5}\)=4\sqrt{10}). In exams use identities to avoid long calculation.
Step 2
Why this answer is correct
The correct answer is A. \(4\sqrt{10}\). (x-2-y-2=(x-y)(x+y)=\(2\sqrt{2}\)\(2\sqrt{5}\)=4\sqrt{10}). In exams use identities to avoid long calculation.
Step 3
Exam Tip
(x-2-y-2=(x-y)(x+y)=\(2\sqrt{2}\)\(2\sqrt{5}\)=4\sqrt{10}) है। परीक्षा में पहचान का प्रयोग करके लंबी गणना बचाएं।
The principal square root is always non-negative, so \(\sqrt{a^2}=|a|\). In exams do not forget the possibility of negative (a).
Step 2
Why this answer is correct
The correct answer is A. \(\sqrt{a^2}=|a|\). The principal square root is always non-negative, so \(\sqrt{a^2}=|a|\). In exams do not forget the possibility of negative (a).
Step 3
Exam Tip
मुख्य वर्गमूल हमेशा अऋणात्मक होता है, इसलिए \(\sqrt{a^2}=|a|\) है। परीक्षा में (a) ऋणात्मक होने की संभावना न भूलें।
A. \(4+\sqrt{5}\) और \(4-\sqrt{5}\)/\(4+\sqrt{5}\) and \(4-\sqrt{5}\)
Step 1
Concept
The sum of \(4+\sqrt{5}\) and \(4-\sqrt{5}\) is (8), and the product is (16-5=11). In exams check the sum and product of options.
Step 2
Why this answer is correct
The correct answer is A. \(4+\sqrt{5}\) और \(4-\sqrt{5}\) / \(4+\sqrt{5}\) and \(4-\sqrt{5}\). The sum of \(4+\sqrt{5}\) and \(4-\sqrt{5}\) is (8), and the product is (16-5=11). In exams check the sum and product of options.
Step 3
Exam Tip
\(4+\sqrt{5}\) और \(4-\sqrt{5}\) का योग (8) और गुणनफल (16-5=11) है। परीक्षा में विकल्पों का योग और गुणनफल जांचें।
\(\sqrt{50}=5\sqrt{2}\) and \(\sqrt{32}=4\sqrt{2}\), so the value is \(2\sqrt{2}\). In exams handle signs carefully.
Step 2
Why this answer is correct
The correct answer is A. \(2\sqrt{2}\). \(\sqrt{50}=5\sqrt{2}\) and \(\sqrt{32}=4\sqrt{2}\), so the value is \(2\sqrt{2}\). In exams handle signs carefully.
Step 3
Exam Tip
\(\sqrt{50}=5\sqrt{2}\) और \(\sqrt{32}=4\sqrt{2}\), इसलिए मान \(2\sqrt{2}\) है। परीक्षा में चिन्हों को सावधानी से रखें।
The discriminant is (100-92=8), and \(\sqrt{8}\) is irrational, so the zeroes are real irrational. In exams check the square root of the discriminant.
Step 2
Why this answer is correct
The correct answer is A. वास्तविक अपरिमेय / Real irrational. The discriminant is (100-92=8), and \(\sqrt{8}\) is irrational, so the zeroes are real irrational. In exams check the square root of the discriminant.
Step 3
Exam Tip
विविक्तकर (100-92=8) है और \(\sqrt{8}\) अपरिमेय है, इसलिए शून्यक वास्तविक अपरिमेय हैं। परीक्षा में विविक्तकर का वर्गमूल देखें।
\(\sqrt{20}+\sqrt{45}=2\sqrt{5}+3\sqrt{5}=5\sqrt{5}\), which is irrational. In exams do not treat addition like multiplication.
Step 2
Why this answer is correct
The correct answer is A. \(\sqrt{20}+\sqrt{45}\). \(\sqrt{20}+\sqrt{45}=2\sqrt{5}+3\sqrt{5}=5\sqrt{5}\), which is irrational. In exams do not treat addition like multiplication.
Step 3
Exam Tip
\(\sqrt{20}+\sqrt{45}=2\sqrt{5}+3\sqrt{5}=5\sqrt{5}\), जो अपरिमेय है। परीक्षा में योग को गुणन जैसा न मानें।
After simplification, (7) remains in the denominator, so the decimal is non-terminating recurring. In exams do not decide only from the original denominator.
Step 2
Why this answer is correct
The correct answer is A. अनवसानी आवर्ती / Non-terminating recurring. After simplification, (7) remains in the denominator, so the decimal is non-terminating recurring. In exams do not decide only from the original denominator.
Step 3
Exam Tip
सरलीकरण के बाद हर में (7) बचता है, इसलिए दशमलव अनवसानी आवर्ती होगा। परीक्षा में केवल मूल हर देखकर निर्णय न लें।
