Concept-wise Practice

quadratic-roots MCQ Questions for Class 10

quadratic-roots se related questions ko ek jagah revise karein. Har question me bilingual content, answer feedback aur explanation available hai.

Practice Questions

200 questions tagged with quadratic-roots.

यदि \(x^2-6x+8=0\) की जड़ें \(\alpha,\beta\) हैं, तो (\(\alpha-2\)\(\beta-2\)) का मान क्या है?

If \(\alpha,\beta\) are roots of \(x^2-6x+8=0\), what is (\(\alpha-2\)\(\beta-2\))?

Explanation opens after your attempt
Correct Answer

A. (0)

Step 1

Concept

(\(\alpha-2\)\(\beta-2\)=\alpha\beta-2\(\alpha+\beta\)+4). Since \(\alpha+\beta=6\) and \(\alpha\beta=8\), the value is (0).

Step 2

Why this answer is correct

The correct answer is A. (0). (\(\alpha-2\)\(\beta-2\)=\alpha\beta-2\(\alpha+\beta\)+4). Since \(\alpha+\beta=6\) and \(\alpha\beta=8\), the value is (0).

Step 3

Exam Tip

(\(\alpha-2\)\(\beta-2\)=\alpha\beta-2\(\alpha+\beta\)+4) है। \(\alpha+\beta=6\) और \(\alpha\beta=8\), इसलिए मान (0) है।

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((k-2)x-2+4x+1=0) की जड़ें समान हों, तो (k) का मान क्या है?

If ((k-2)x-2+4x+1=0) has equal roots, what is (k)?

Explanation opens after your attempt
Correct Answer

A. (6)

Step 1

Concept

For equal roots, put (D=0). From (16-4(k-2)=0), we get (k=6).

Step 2

Why this answer is correct

The correct answer is A. (6). For equal roots, put (D=0). From (16-4(k-2)=0), we get (k=6).

Step 3

Exam Tip

समान जड़ों के लिए (D=0) रखें। (16-4(k-2)=0) से (k=6) मिलता है।

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\(x^2-sx+9=0\) की जड़ें समान और धनात्मक हों, तो (s) का मान क्या होगा?

If \(x^2-sx+9=0\) has equal and positive roots, what is (s)?

Explanation opens after your attempt
Correct Answer

A. (6)

Step 1

Concept

For equal roots, \(s^2-36=0\), so \(s=\pm6\). The equal root is \(\frac{s}{2}\), which is positive when (s=6).

Step 2

Why this answer is correct

The correct answer is A. (6). For equal roots, \(s^2-36=0\), so \(s=\pm6\). The equal root is \(\frac{s}{2}\), which is positive when (s=6).

Step 3

Exam Tip

समान जड़ों के लिए \(s^2-36=0\), इसलिए \(s=\pm6\)। समान जड़ \(\frac{s}{2}\) है, जो धनात्मक होने पर (s=6) देता है।

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\(x^2+3x-18=0\) की जड़ों का सही युग्म कौन-सा है?

Which is the correct pair of roots of \(x^2+3x-18=0\)?

Explanation opens after your attempt
Correct Answer

A. (3) और (-6)(3) and (-6)

Step 1

Concept

The numbers with product (-18) and sum (-3) are (3) and (-6). Hence this is the correct pair of roots.

Step 2

Why this answer is correct

The correct answer is A. (3) और (-6) / (3) and (-6). The numbers with product (-18) and sum (-3) are (3) and (-6). Hence this is the correct pair of roots.

Step 3

Exam Tip

गुणनफल (-18) और योग (-3) वाली संख्याएँ (3) और (-6) हैं। इसलिए यही जड़ों का सही युग्म है।

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\(4x^2-4x+1=0\) की दोनों जड़ों का मान क्या है?

What is the value of both roots of \(4x^2-4x+1=0\)?

Explanation opens after your attempt
Correct Answer

A. \(\frac{1}{2}\)

Step 1

Concept

(4x-2-4x+1=(2x-1)2). Therefore the equal root is \(x=\frac{1}{2}\).

Step 2

Why this answer is correct

The correct answer is A. \(\frac{1}{2}\). (4x-2-4x+1=(2x-1)2). Therefore the equal root is \(x=\frac{1}{2}\).

Step 3

Exam Tip

(4x-2-4x+1=(2x-1)2) है। इसलिए समान जड़ \(x=\frac{1}{2}\) है।

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यदि (x=0), \(ax^2+bx+c=0\) की जड़ है, तो कौन-सी शर्त निश्चित रूप से सही है?

If (x=0) is a root of \(ax^2+bx+c=0\), which condition must be true?

Explanation opens after your attempt
Correct Answer

A. (c=0)

Step 1

Concept

Putting (x=0) gives (c=0). Thus the direct condition for zero to be a root is (c=0).

Step 2

Why this answer is correct

The correct answer is A. (c=0). Putting (x=0) gives (c=0). Thus the direct condition for zero to be a root is (c=0).

Step 3

Exam Tip

(x=0) रखने पर समीकरण (c=0) बनता है। इसलिए शून्य जड़ होने की सीधी शर्त (c=0) है।

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\(x^2+6x+r=0\) की जड़ों का अंतर \(2\sqrt{5}\) है, तो (r) का मान क्या है?

If the difference between the roots of \(x^2+6x+r=0\) is \(2\sqrt{5}\), what is (r)?

Explanation opens after your attempt
Correct Answer

A. (4)

Step 1

Concept

Using (\(\alpha-\beta\)2=\(\alpha+\beta\)2-4\alpha\beta), we get (20=36-4r). Hence (r=4).

Step 2

Why this answer is correct

The correct answer is A. (4). Using (\(\alpha-\beta\)2=\(\alpha+\beta\)2-4\alpha\beta), we get (20=36-4r). Hence (r=4).

Step 3

Exam Tip

(\(\alpha-\beta\)2=\(\alpha+\beta\)2-4\alpha\beta) से (20=36-4r) मिलता है। इसलिए (r=4)।

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यदि \(x^2-4x+2=0\) की जड़ें \(\alpha,\beta\) हैं, तो (\(\alpha+2\)\(\beta+2\)) का मान क्या है?

If \(\alpha,\beta\) are roots of \(x^2-4x+2=0\), what is (\(\alpha+2\)\(\beta+2\))?

Explanation opens after your attempt
Correct Answer

C. (14)

Step 1

Concept

(\(\alpha+2\)\(\beta+2\)=\alpha\beta+2\(\alpha+\beta\)+4). Since \(\alpha+\beta=4\) and \(\alpha\beta=2\), the value is (14).

Step 2

Why this answer is correct

The correct answer is C. (14). (\(\alpha+2\)\(\beta+2\)=\alpha\beta+2\(\alpha+\beta\)+4). Since \(\alpha+\beta=4\) and \(\alpha\beta=2\), the value is (14).

Step 3

Exam Tip

(\(\alpha+2\)\(\beta+2\)=\alpha\beta+2\(\alpha+\beta\)+4) है। \(\alpha+\beta=4\) और \(\alpha\beta=2\), इसलिए मान (14) है।

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\(2x^2+kx+2=0\) की जड़ें समान और ऋणात्मक हों, तो (k) का मान क्या होगा?

If \(2x^2+kx+2=0\) has equal and negative roots, what is (k)?

Explanation opens after your attempt
Correct Answer

A. (4)

Step 1

Concept

For equal roots, \(k^2-16=0\), so \(k=\pm4\). The equal root is \(-\frac{k}{4}\), which is negative only when (k=4).

Step 2

Why this answer is correct

The correct answer is A. (4). For equal roots, \(k^2-16=0\), so \(k=\pm4\). The equal root is \(-\frac{k}{4}\), which is negative only when (k=4).

Step 3

Exam Tip

समान जड़ों के लिए \(k^2-16=0\), इसलिए \(k=\pm4\)। समान जड़ \(-\frac{k}{4}\) है, जो ऋणात्मक तभी होगी जब (k=4)।

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(x-2-(m+1)x+m=0) की जड़ें एक-दूसरे की व्युत्क्रम हों, तो (m) का मान क्या है?

If the roots of (x-2-(m+1)x+m=0) are reciprocals of each other, what is (m)?

Explanation opens after your attempt
Correct Answer

A. (1)

Step 1

Concept

For reciprocal roots, \(\alpha\beta=1\). Here \(\alpha\beta=m\), so (m=1).

Step 2

Why this answer is correct

The correct answer is A. (1). For reciprocal roots, \(\alpha\beta=1\). Here \(\alpha\beta=m\), so (m=1).

Step 3

Exam Tip

व्युत्क्रम जड़ों के लिए \(\alpha\beta=1\) होता है। यहाँ \(\alpha\beta=m\), इसलिए (m=1)।

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\(x^2+2x+c=0\) की जड़ें वास्तविक हैं और जड़ों का गुणनफल उनके योग से कम है, तो (c) पर सही शर्त क्या है?

For \(x^2+2x+c=0\), the roots are real and their product is less than their sum. What is the correct condition on (c)?

Explanation opens after your attempt
Correct Answer

A. (c<-2)

Step 1

Concept

The sum is (-2) and the product is (c), so (c<-2) is needed. This condition also satisfies (D=4-4c>0).

Step 2

Why this answer is correct

The correct answer is A. (c<-2). The sum is (-2) and the product is (c), so (c<-2) is needed. This condition also satisfies (D=4-4c>0).

Step 3

Exam Tip

योग (-2) और गुणनफल (c) है, इसलिए (c<-2) चाहिए। यह शर्त (D=4-4c>0) को भी पूरा करती है।

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\(x^2-10x+k=0\) की जड़ें भिन्न अभाज्य संख्याएँ हैं, तो (k) का मान क्या है?

The roots of \(x^2-10x+k=0\) are distinct prime numbers. What is (k)?

Explanation opens after your attempt
Correct Answer

A. (21)

Step 1

Concept

The distinct prime roots with sum (10) are (3) and (7). Their product is (21), so (k=21).

Step 2

Why this answer is correct

The correct answer is A. (21). The distinct prime roots with sum (10) are (3) and (7). Their product is (21), so (k=21).

Step 3

Exam Tip

योग (10) वाली भिन्न अभाज्य जड़ें (3) और (7) हैं। उनका गुणनफल (21) है, इसलिए (k=21)।

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(x-2-(a+3)x+3a=0) के बारे में कौन-सा कथन हमेशा सही है?

Which statement is always true about (x-2-(a+3)x+3a=0)?

Explanation opens after your attempt
Correct Answer

A. (3) हमेशा एक जड़ है(3) is always a root

Step 1

Concept

Putting (x=3) gives (9-3(a+3)+3a=0). Hence (3) is always one root, and the other root is (a).

Step 2

Why this answer is correct

The correct answer is A. (3) हमेशा एक जड़ है / (3) is always a root. Putting (x=3) gives (9-3(a+3)+3a=0). Hence (3) is always one root, and the other root is (a).

Step 3

Exam Tip

(x=3) रखने पर (9-3(a+3)+3a=0) मिलता है। इसलिए (3) हमेशा एक जड़ है और दूसरी जड़ (a) होती है।

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यदि \(x^2+mx+n=0\) की जड़ें \(\alpha,\beta\) हैं, \(\alpha-\beta=4\) और \(\alpha\beta=5\), तो \(m^2\) क्या है?

If \(\alpha,\beta\) are roots of \(x^2+mx+n=0\), \(\alpha-\beta=4\), and \(\alpha\beta=5\), what is \(m^2\)?

Explanation opens after your attempt
Correct Answer

C. (36)

Step 1

Concept

Use (\(\alpha-\beta\)2=\(\alpha+\beta\)2-4\alpha\beta). Since (16=\(\alpha+\beta\)2-20), we get (\(\alpha+\beta\)2=36) and \(m^2=36\).

Step 2

Why this answer is correct

The correct answer is C. (36). Use (\(\alpha-\beta\)2=\(\alpha+\beta\)2-4\alpha\beta). Since (16=\(\alpha+\beta\)2-20), we get (\(\alpha+\beta\)2=36) and \(m^2=36\).

Step 3

Exam Tip

(\(\alpha-\beta\)2=\(\alpha+\beta\)2-4\alpha\beta) लगाएँ। (16=\(\alpha+\beta\)2-20), इसलिए (\(\alpha+\beta\)2=36) और \(m^2=36\)।

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यदि किसी द्विघात समीकरण की जड़ें (3) और (-2) हैं और \(x^2\) का गुणांक (2) है, तो समीकरण कौन-सा है?

If the roots of a quadratic equation are (3) and (-2), and the coefficient of \(x^2\) is (2), which is the equation?

Explanation opens after your attempt
Correct Answer

A. \(2x^2-2x-12=0\)

Step 1

Concept

The monic equation is \(x^2-x-6=0\). Since the coefficient of \(x^2\) must be (2), multiply the whole equation by (2).

Step 2

Why this answer is correct

The correct answer is A. \(2x^2-2x-12=0\). The monic equation is \(x^2-x-6=0\). Since the coefficient of \(x^2\) must be (2), multiply the whole equation by (2).

Step 3

Exam Tip

मॉनिक समीकरण \(x^2-x-6=0\) है। \(x^2\) का गुणांक (2) चाहिए, इसलिए पूरे समीकरण को (2) से गुणा करें।

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यदि \(x^2-5x+1=0\) की जड़ें \(\alpha,\beta\) हैं, तो \(\alpha^2+\beta^2\) का मान क्या है?

If \(\alpha,\beta\) are roots of \(x^2-5x+1=0\), what is \(\alpha^2+\beta^2\)?

Explanation opens after your attempt
Correct Answer

C. (23)

Step 1

Concept

Here \(\alpha+\beta=5\) and \(\alpha\beta=1\). Thus \(\alpha^2+\beta^2=25-2=23\).

Step 2

Why this answer is correct

The correct answer is C. (23). Here \(\alpha+\beta=5\) and \(\alpha\beta=1\). Thus \(\alpha^2+\beta^2=25-2=23\).

Step 3

Exam Tip

\(\alpha+\beta=5\) और \(\alpha\beta=1\) है। इसलिए \(\alpha^2+\beta^2=25-2=23\)।

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(x-2-2(k+1)x+k-2=0) की जड़ें वास्तविक और भिन्न हों, तो (k) पर सही शर्त क्या है?

For (x-2-2(k+1)x+k-2=0) to have real and distinct roots, what is the correct condition on (k)?

Explanation opens after your attempt
Correct Answer

A. \(k>-\frac{1}{2}\)

Step 1

Concept

For real and distinct roots, (D>0) is needed. Here (D=4(2k+1)), so \(k>-\frac{1}{2}\).

Step 2

Why this answer is correct

The correct answer is A. \(k>-\frac{1}{2}\). For real and distinct roots, (D>0) is needed. Here (D=4(2k+1)), so \(k>-\frac{1}{2}\).

Step 3

Exam Tip

वास्तविक और भिन्न जड़ों के लिए (D>0) चाहिए। यहाँ (D=4(2k+1)), इसलिए \(k>-\frac{1}{2}\)।

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यदि \(x^2+px+q=0\) की जड़ें \(\alpha,\beta\) हैं और \(\alpha+1,\beta+1\), \(x^2-5x+6=0\) की जड़ें हैं, तो (p,q) क्या होंगे?

If \(\alpha,\beta\) are the roots of \(x^2+px+q=0\) and \(\alpha+1,\beta+1\) are the roots of \(x^2-5x+6=0\), what are (p,q)?

Explanation opens after your attempt
Correct Answer

A. (p=-3,\ q=2)

Step 1

Concept

The sum of new roots is \(\alpha+\beta+2=5\), so (p=-3). From product (q-p+1=6), we get (q=2).

Step 2

Why this answer is correct

The correct answer is A. (p=-3,\ q=2). The sum of new roots is \(\alpha+\beta+2=5\), so (p=-3). From product (q-p+1=6), we get (q=2).

Step 3

Exam Tip

नई जड़ों का योग \(\alpha+\beta+2=5\) है, इसलिए (p=-3)। गुणनफल (q-p+1=6) से (q=2) मिलता है।

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\(\frac{1}{2}\) और \(\frac{3}{4}\) जड़ों वाला द्विघात समीकरण कौन-सा है?

Which quadratic equation has roots \(\frac{1}{2}\) and \(\frac{3}{4}\)?

Explanation opens after your attempt
Correct Answer

A. \(8x^2-10x+3=0\)

Step 1

Concept

The sum is \(\frac{5}{4}\) and the product is \(\frac{3}{8}\). Multiply \(x^2-\frac{5}{4}x+\frac{3}{8}=0\) by (8).

Step 2

Why this answer is correct

The correct answer is A. \(8x^2-10x+3=0\). The sum is \(\frac{5}{4}\) and the product is \(\frac{3}{8}\). Multiply \(x^2-\frac{5}{4}x+\frac{3}{8}=0\) by (8).

Step 3

Exam Tip

जड़ों का योग \(\frac{5}{4}\) और गुणनफल \(\frac{3}{8}\) है। समीकरण \(x^2-\frac{5}{4}x+\frac{3}{8}=0\) को (8) से गुणा करें।

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यदि \(x^2+ax+12=0\) की एक जड़ दूसरी जड़ से (3) अधिक है, तो (a) के संभव मान क्या हैं?

If one root of \(x^2+ax+12=0\) is (3) more than the other root, what are the possible values of (a)?

Explanation opens after your attempt
Correct Answer

A. \(\sqrt{57}\) और \(-\sqrt{57}\)\(\sqrt{57}\) and \(-\sqrt{57}\)

Step 1

Concept

Let the roots be (r) and (r+3). Then (r(r+3)=12), giving the sum as \(\pm\sqrt{57}\), so \(a=\mp\sqrt{57}\).

Step 2

Why this answer is correct

The correct answer is A. \(\sqrt{57}\) और \(-\sqrt{57}\) / \(\sqrt{57}\) and \(-\sqrt{57}\). Let the roots be (r) and (r+3). Then (r(r+3)=12), giving the sum as \(\pm\sqrt{57}\), so \(a=\mp\sqrt{57}\).

Step 3

Exam Tip

जड़ें (r) और (r+3) मानने पर (r(r+3)=12) मिलता है। इससे जड़ों का योग \(\pm\sqrt{57}\) होता है, इसलिए \(a=\mp\sqrt{57}\)।

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\(x^2+kx+16=0\) की जड़ें समान हों, तो (k) के संभव मान क्या हैं?

If \(x^2+kx+16=0\) has equal roots, what are the possible values of (k)?

Explanation opens after your attempt
Correct Answer

A. (8) और (-8)(8) and (-8)

Step 1

Concept

For equal roots, \(k^2-64=0\) must hold. Hence \(k=\pm8\).

Step 2

Why this answer is correct

The correct answer is A. (8) और (-8) / (8) and (-8). For equal roots, \(k^2-64=0\) must hold. Hence \(k=\pm8\).

Step 3

Exam Tip

समान जड़ों के लिए \(k^2-64=0\) होना चाहिए। अतः \(k=\pm8\) है।

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यदि \(2x^2+3x-5=0\) की जड़ें \(\alpha,\beta\) हैं, तो \(\alpha^2\beta+\alpha\beta^2\) का मान क्या है?

If \(\alpha,\beta\) are roots of \(2x^2+3x-5=0\), what is \(\alpha^2\beta+\alpha\beta^2\)?

Explanation opens after your attempt
Correct Answer

A. \(\frac{15}{4}\)

Step 1

Concept

(\alpha-2\beta+\alpha\beta-2=\alpha\beta\(\alpha+\beta\)). Since \(\alpha\beta=-\frac{5}{2}\) and \(\alpha+\beta=-\frac{3}{2}\), the value is \(\frac{15}{4}\).

Step 2

Why this answer is correct

The correct answer is A. \(\frac{15}{4}\). (\alpha-2\beta+\alpha\beta-2=\alpha\beta\(\alpha+\beta\)). Since \(\alpha\beta=-\frac{5}{2}\) and \(\alpha+\beta=-\frac{3}{2}\), the value is \(\frac{15}{4}\).

Step 3

Exam Tip

(\alpha-2\beta+\alpha\beta-2=\alpha\beta\(\alpha+\beta\)) होता है। \(\alpha\beta=-\frac{5}{2}\) और \(\alpha+\beta=-\frac{3}{2}\), इसलिए मान \(\frac{15}{4}\) है।

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(x-2-2x+(p+3)=0) की वास्तविक जड़ें न हों, इसके लिए (p) पर सही शर्त क्या है?

For (x-2-2x+(p+3)=0) to have no real roots, what is the correct condition on (p)?

Explanation opens after your attempt
Correct Answer

A. (p>-2)

Step 1

Concept

For no real roots, (D<0) is required. Here (D=-4(p+2)), so (p>-2).

Step 2

Why this answer is correct

The correct answer is A. (p>-2). For no real roots, (D<0) is required. Here (D=-4(p+2)), so (p>-2).

Step 3

Exam Tip

वास्तविक जड़ें न होने के लिए (D<0) चाहिए। यहाँ (D=-4(p+2)), इसलिए (p>-2) है।

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सामान्य द्विघात समीकरण \(ax^2+bx+c=0\) में जड़ें समान हों, तो सही संबंध कौन-सा है?

For the general quadratic equation \(ax^2+bx+c=0\), which relation is correct when the roots are equal?

Explanation opens after your attempt
Correct Answer

A. \(b^2=4ac\)

Step 1

Concept

For equal real roots, the discriminant \(D=b^2-4ac=0\). Therefore \(b^2=4ac\) is the correct relation.

Step 2

Why this answer is correct

The correct answer is A. \(b^2=4ac\). For equal real roots, the discriminant \(D=b^2-4ac=0\). Therefore \(b^2=4ac\) is the correct relation.

Step 3

Exam Tip

समान वास्तविक जड़ों के लिए विविक्तकर \(D=b^2-4ac=0\) होता है। इसलिए \(b^2=4ac\) सही संबंध है।

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(x-2-(k+2)x+2k=0) की जड़ों का अंतर (2) है, तो (k) के मान क्या हैं?

If the difference between the roots of (x-2-(k+2)x+2k=0) is (2), what are the values of (k)?

Explanation opens after your attempt
Correct Answer

A. (0) और (4)(0) and (4)

Step 1

Concept

(\(\alpha-\beta\)2=(k+2)2-8k=(k-2)2). Setting it equal to (4) gives (k=0) or (k=4).

Step 2

Why this answer is correct

The correct answer is A. (0) और (4) / (0) and (4). (\(\alpha-\beta\)2=(k+2)2-8k=(k-2)2). Setting it equal to (4) gives (k=0) or (k=4).

Step 3

Exam Tip

(\(\alpha-\beta\)2=(k+2)2-8k=(k-2)2) है। इसे (4) रखने पर (k=0) या (k=4) मिलता है।

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यदि \(x^2-7x+10=0\) की जड़ें \(\alpha,\beta\) हैं, तो \(\frac{1}{\alpha-1}+\frac{1}{\beta-1}\) का मान क्या है?

If \(\alpha,\beta\) are roots of \(x^2-7x+10=0\), what is \(\frac{1}{\alpha-1}+\frac{1}{\beta-1}\)?

Explanation opens after your attempt
Correct Answer

A. \(\frac{5}{4}\)

Step 1

Concept

The denominator (\(\alpha-1\)\(\beta-1\)=\alpha\beta-\(\alpha+\beta\)+1=4). The numerator is \(\alpha+\beta-2=5\), so the value is \(\frac{5}{4}\).

Step 2

Why this answer is correct

The correct answer is A. \(\frac{5}{4}\). The denominator (\(\alpha-1\)\(\beta-1\)=\alpha\beta-\(\alpha+\beta\)+1=4). The numerator is \(\alpha+\beta-2=5\), so the value is \(\frac{5}{4}\).

Step 3

Exam Tip

हर (\(\alpha-1\)\(\beta-1\)=\alpha\beta-\(\alpha+\beta\)+1=4) है। ऊपर \(\alpha+\beta-2=5\), इसलिए मान \(\frac{5}{4}\) है।

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\(2x^2+\lambda x+8=0\) की जड़ें समान हों, तो \(\lambda\) के मान क्या होंगे?

If \(2x^2+\lambda x+8=0\) has equal roots, what are the values of \(\lambda\)?

Explanation opens after your attempt
Correct Answer

A. (8) और (-8)(8) and (-8)

Step 1

Concept

For equal roots, put (D=0). From \(\lambda^2-64=0\), we get \(\lambda=\pm8\).

Step 2

Why this answer is correct

The correct answer is A. (8) और (-8) / (8) and (-8). For equal roots, put (D=0). From \(\lambda^2-64=0\), we get \(\lambda=\pm8\).

Step 3

Exam Tip

समान जड़ों के लिए (D=0) रखें। \(\lambda^2-64=0\) से \(\lambda=\pm8\) मिलता है।

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\(x^2-4x+k=0\) की जड़ें वास्तविक और व्युत्क्रम हों, तो (k) का मान क्या है?

If the roots of \(x^2-4x+k=0\) are real and reciprocal, what is (k)?

Explanation opens after your attempt
Correct Answer

A. (1)

Step 1

Concept

For reciprocal roots, \(\alpha\beta=1\). Here \(\alpha\beta=k\), so (k=1), and (D=12>0) confirms real roots.

Step 2

Why this answer is correct

The correct answer is A. (1). For reciprocal roots, \(\alpha\beta=1\). Here \(\alpha\beta=k\), so (k=1), and (D=12>0) confirms real roots.

Step 3

Exam Tip

व्युत्क्रम जड़ों के लिए \(\alpha\beta=1\) होता है। यहाँ \(\alpha\beta=k\), इसलिए (k=1), और (D=12>0) से जड़ें वास्तविक भी हैं।

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यदि किसी द्विघात समीकरण की जड़ें \(2+\sqrt{5}\) और \(2-\sqrt{5}\) हैं, तो समीकरण कौन-सा है?

If the roots of a quadratic equation are \(2+\sqrt{5}\) and \(2-\sqrt{5}\), which is the equation?

Explanation opens after your attempt
Correct Answer

A. \(x^2-4x-1=0\)

Step 1

Concept

\(The sum of roots is (4) and the product is (-1). Use (x^2-(\)sum)x+product\(=0) to get the answer.\)

Step 2

Why this answer is correct

\(The correct answer is A. (x^2-4x-1=0). The sum of roots is (4) and the product is (-1). Use (x^2-(\)sum)x+product\(=0) to get the answer.\)

Step 3

Exam Tip

जड़ों का योग (4) और गुणनफल (-1) है। \(समीकरण (x^2-(\)योग)x+गुणनफल\(=0) से उत्तर मिलता है\)।

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यदि \(x^2-3x-2=0\) की जड़ें \(\alpha,\beta\) हैं, तो \(\alpha^2,\beta^2\) जड़ों वाला समीकरण कौन-सा है?

If \(\alpha,\beta\) are the roots of \(x^2-3x-2=0\), which equation has roots \(\alpha^2,\beta^2\)?

Explanation opens after your attempt
Correct Answer

A. \(x^2-13x+4=0\)

Step 1

Concept

Here \(\alpha+\beta=3\) and \(\alpha\beta=-2\). Thus \(\alpha^2+\beta^2=13\) and \(\alpha^2\beta^2=4\), so the equation is \(x^2-13x+4=0\).

Step 2

Why this answer is correct

The correct answer is A. \(x^2-13x+4=0\). Here \(\alpha+\beta=3\) and \(\alpha\beta=-2\). Thus \(\alpha^2+\beta^2=13\) and \(\alpha^2\beta^2=4\), so the equation is \(x^2-13x+4=0\).

Step 3

Exam Tip

\(\alpha+\beta=3\) और \(\alpha\beta=-2\) है। इसलिए \(\alpha^2+\beta^2=13\) और \(\alpha^2\beta^2=4\), अतः समीकरण \(x^2-13x+4=0\) है।

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