Since \(\alpha\) is a root, \(\alpha^2=5\alpha+3\), and \(\alpha\beta=-3\). The expression becomes (5\alpha+3+5\beta-3=5\(\alpha+\beta\)=25).
Step 2
Why this answer is correct
The correct answer is C. (25). Since \(\alpha\) is a root, \(\alpha^2=5\alpha+3\), and \(\alpha\beta=-3\). The expression becomes (5\alpha+3+5\beta-3=5\(\alpha+\beta\)=25).
Step 3
Exam Tip
क्योंकि \(\alpha\) जड़ है, \(\alpha^2=5\alpha+3\) और \(\alpha\beta=-3\) है। व्यंजक (5\alpha+3+5\beta-3=5\(\alpha+\beta\)=25) बनता है।
Here \(\alpha+\beta=3\) and \(\alpha\beta=\frac{5}{4}\). Thus \(\alpha^3+\beta^3=27-\frac{45}{4}=\frac{63}{4}\).
Step 2
Why this answer is correct
The correct answer is A. \(\frac{63}{4}\). Here \(\alpha+\beta=3\) and \(\alpha\beta=\frac{5}{4}\). Thus \(\alpha^3+\beta^3=27-\frac{45}{4}=\frac{63}{4}\).
Step 3
Exam Tip
यहाँ \(\alpha+\beta=3\) और \(\alpha\beta=\frac{5}{4}\) है। \(\alpha^3+\beta^3=27-\frac{45}{4}=\frac{63}{4}\)।
Here \(\alpha+\beta=3\) and \(\alpha\beta=\frac{5}{4}\). Using (\alpha-3+\beta-3=\(\alpha+\beta\)3-3\alpha\beta\(\alpha+\beta\)), we get \(\frac{63}{4}\), so none of the options is correct.
Step 2
Why this answer is correct
The correct answer is A. \(\frac{81}{8}\). Here \(\alpha+\beta=3\) and \(\alpha\beta=\frac{5}{4}\). Using (\alpha-3+\beta-3=\(\alpha+\beta\)3-3\alpha\beta\(\alpha+\beta\)), we get \(\frac{63}{4}\), so none of the options is correct.
Step 3
Exam Tip
यहाँ \(\alpha+\beta=3\) और \(\alpha\beta=\frac{5}{4}\) है। (\alpha-3+\beta-3=\(\alpha+\beta\)3-3\alpha\beta\(\alpha+\beta\)=\frac{63}{4}), इसलिए विकल्पों में कोई सही नहीं है।
The roots are (5) and (6). Direct substitution gives \(\frac{6}{4}+\frac{7}{5}=\frac{29}{10}\), so none of the given options is correct.
Step 2
Why this answer is correct
The correct answer is B. \(\frac{19}{5}\). The roots are (5) and (6). Direct substitution gives \(\frac{6}{4}+\frac{7}{5}=\frac{29}{10}\), so none of the given options is correct.
Step 3
Exam Tip
जड़ें (5) और (6) हैं। सीधे रखने पर \(\frac{6}{4}+\frac{7}{5}=\frac{29}{10}\), इसलिए दिए गए विकल्पों में कोई सही नहीं है।
The roots are (4) and (5). Direct substitution gives \(\frac{6}{2}+\frac{7}{3}=\frac{16}{3}\), so option (A) should be correct.
Step 2
Why this answer is correct
The correct answer is B. \(\frac{17}{3}\). The roots are (4) and (5). Direct substitution gives \(\frac{6}{2}+\frac{7}{3}=\frac{16}{3}\), so option (A) should be correct.
Step 3
Exam Tip
जड़ें (4) और (5) हैं। सीधे रखने पर \(\frac{6}{2}+\frac{7}{3}=\frac{16}{3}\) मिलता है, इसलिए विकल्प (A) सही होना चाहिए।
For real roots, \(D\ge0\) is required. Here (D=36(a-1)2-36\(a^2-4a-5\)=72a+216), so the exact condition is \(a\ge-3\), not \(a\ge-\frac{7}{2}\).
Step 2
Why this answer is correct
The correct answer is A. \(a\ge-\frac{7}{2}\). For real roots, \(D\ge0\) is required. Here (D=36(a-1)2-36\(a^2-4a-5\)=72a+216), so the exact condition is \(a\ge-3\), not \(a\ge-\frac{7}{2}\).
Step 3
Exam Tip
वास्तविक जड़ों के लिए \(D\ge0\) चाहिए। यहाँ (D=36(a-1)2-36\(a^2-4a-5\)=72a+216), इसलिए \(a\ge-\frac{7}{2}\) नहीं बल्कि \(a\ge-3\) होगा।
For real roots, \(D\ge0\) is required. Here (D=64(a-2)2-64\(a^2-6a\)=128(a+2)), so \(a\ge-2\); hence none of these options is exact.
Step 2
Why this answer is correct
The correct answer is A. \(a\ge1\). For real roots, \(D\ge0\) is required. Here (D=64(a-2)2-64\(a^2-6a\)=128(a+2)), so \(a\ge-2\); hence none of these options is exact.
Step 3
Exam Tip
वास्तविक जड़ों के लिए \(D\ge0\) चाहिए। यहाँ (D=64(a-2)2-64\(a^2-6a\)=128(a+2)), इसलिए \(a\ge-2\) होगा, अतः विकल्पों में सही शर्त नहीं है।
From (r(r+2)=24), we get (r=4) or (r=-6). The sum of roots is (10) or (-10), so (p=-10) or (p=10).
Step 2
Why this answer is correct
The correct answer is A. (10) और (-10) / (10) and (-10). From (r(r+2)=24), we get (r=4) or (r=-6). The sum of roots is (10) or (-10), so (p=-10) or (p=10).
Step 3
Exam Tip
(r(r+2)=24) से (r=4) या (r=-6) मिलता है। जड़ों का योग (10) या (-10) है, इसलिए (p=-10) या (p=10)।
A. \(k\neq0\) और \(k^2\le36\)/\(k\neq0\) and \(k^2\le36\)
Step 1
Concept
The product of roots is \(\frac{k}{k}=1\), so \(k\neq0\) is needed. For real roots, \(144-4k^2\ge0\), hence \(k^2\le36\).
Step 2
Why this answer is correct
The correct answer is A. \(k\neq0\) और \(k^2\le36\) / \(k\neq0\) and \(k^2\le36\). The product of roots is \(\frac{k}{k}=1\), so \(k\neq0\) is needed. For real roots, \(144-4k^2\ge0\), hence \(k^2\le36\).
Step 3
Exam Tip
जड़ों का गुणनफल \(\frac{k}{k}=1\) है, इसलिए \(k\neq0\) चाहिए। वास्तविक जड़ों के लिए \(144-4k^2\ge0\), अतः \(k^2\le36\)।
Here \(\alpha^2+\beta^2=64-4=60\) and (\(\alpha\beta\)2=4). Thus \(\frac{1}{\alpha^2}+\frac{1}{\beta^2}=\frac{60}{4}=15\).
Step 2
Why this answer is correct
The correct answer is A. (15). Here \(\alpha^2+\beta^2=64-4=60\) and (\(\alpha\beta\)2=4). Thus \(\frac{1}{\alpha^2}+\frac{1}{\beta^2}=\frac{60}{4}=15\).
Step 3
Exam Tip
\(\alpha^2+\beta^2=64-4=60\) और (\(\alpha\beta\)2=4) है। इसलिए \(\frac{1}{\alpha^2}+\frac{1}{\beta^2}=\frac{60}{4}=15\)।
Putting (x=8) gives (64-8(a+8)+8a=0). Hence (8) is always one root and the other root is (a).
Step 2
Why this answer is correct
The correct answer is A. (8) हमेशा एक जड़ है / (8) is always one root. Putting (x=8) gives (64-8(a+8)+8a=0). Hence (8) is always one root and the other root is (a).
Step 3
Exam Tip
(x=8) रखने पर (64-8(a+8)+8a=0) मिलता है। इसलिए (8) हमेशा एक जड़ है और दूसरी जड़ (a) है।
A. \(7\sqrt{3}\) और \(-7\sqrt{3}\)/\(7\sqrt{3}\) and \(-7\sqrt{3}\)
Step 1
Concept
Let the roots be (2r) and (5r). From \(10r^2=\frac{10}{3}\), \(r=\pm\frac{1}{\sqrt{3}}\), so \(7r=-\frac{m}{3}\) gives \(m=\pm7\sqrt{3}\).
Step 2
Why this answer is correct
The correct answer is A. \(7\sqrt{3}\) और \(-7\sqrt{3}\) / \(7\sqrt{3}\) and \(-7\sqrt{3}\). Let the roots be (2r) and (5r). From \(10r^2=\frac{10}{3}\), \(r=\pm\frac{1}{\sqrt{3}}\), so \(7r=-\frac{m}{3}\) gives \(m=\pm7\sqrt{3}\).
Step 3
Exam Tip
जड़ें (2r) और (5r) मानें। \(10r^2=\frac{10}{3}\) से \(r=\pm\frac{1}{\sqrt{3}}\), इसलिए \(7r=-\frac{m}{3}\) से \(m=\pm7\sqrt{3}\)।
Here \(\alpha+\beta=\frac{16}{5}\) and \(\alpha\beta=\frac{p}{5}\). Using (\(\alpha-\beta\)2=\(\alpha+\beta\)2-4\alpha\beta), we get (p=11).
Step 2
Why this answer is correct
The correct answer is C. (11). Here \(\alpha+\beta=\frac{16}{5}\) and \(\alpha\beta=\frac{p}{5}\). Using (\(\alpha-\beta\)2=\(\alpha+\beta\)2-4\alpha\beta), we get (p=11).
Step 3
Exam Tip
यहाँ \(\alpha+\beta=\frac{16}{5}\) और \(\alpha\beta=\frac{p}{5}\) है। (\(\alpha-\beta\)2=\(\alpha+\beta\)2-4\alpha\beta) से (p=11) मिलता है।
A. \(m\ge0\) और \(m\neq1\)/\(m\ge0\) and \(m\neq1\)
Step 1
Concept
The product of roots is \(\frac{m-1}{m-1}=1\), so \(m\neq1\) is needed. For real roots, \(D=16m\ge0\), hence \(m\ge0\) and \(m\neq1\).
Step 2
Why this answer is correct
The correct answer is A. \(m\ge0\) और \(m\neq1\) / \(m\ge0\) and \(m\neq1\). The product of roots is \(\frac{m-1}{m-1}=1\), so \(m\neq1\) is needed. For real roots, \(D=16m\ge0\), hence \(m\ge0\) and \(m\neq1\).
Step 3
Exam Tip
जड़ों का गुणनफल \(\frac{m-1}{m-1}=1\) है, इसलिए \(m\neq1\) चाहिए। वास्तविक जड़ों के लिए \(D=16m\ge0\), अतः \(m\ge0\) और \(m\neq1\)।
Here \(\alpha+\beta=5\) and \(\alpha\beta=6\). The new roots are (5) and (6), so the equation is \(x^2-11x+30=0\).
Step 2
Why this answer is correct
The correct answer is A. \(x^2-11x+30=0\). Here \(\alpha+\beta=5\) and \(\alpha\beta=6\). The new roots are (5) and (6), so the equation is \(x^2-11x+30=0\).
Step 3
Exam Tip
\(\alpha+\beta=5\) और \(\alpha\beta=6\) हैं। नई जड़ें (5) और (6) हैं, इसलिए समीकरण \(x^2-11x+30=0\) है।
