Concept-wise Practice

root-expression MCQ Questions for Class 10

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

Practice Questions

42 questions tagged with root-expression.

यदि \(x^2-5x+6=0\) की जड़ें \(\alpha,\beta\) हैं, तो \(\alpha^2-4\alpha+\beta^2-4\beta\) का मान क्या है?

If \(\alpha,\beta\) are roots of \(x^2-5x+6=0\), what is \(\alpha^2-4\alpha+\beta^2-4\beta\)?

Explanation opens after your attempt
Correct Answer

A. (5)

Step 1

Concept

(\alpha-2+\beta-2=\(\alpha+\beta\)2-2\alpha\beta=13). Thus the value is (13-4(5)=-7), so none of the options is correct.

Step 2

Why this answer is correct

The correct answer is A. (5). (\alpha-2+\beta-2=\(\alpha+\beta\)2-2\alpha\beta=13). Thus the value is (13-4(5)=-7), so none of the options is correct.

Step 3

Exam Tip

(\alpha-2+\beta-2=\(\alpha+\beta\)2-2\alpha\beta=13) है। इसलिए मान (13-4(5)=-7) होगा, अतः कोई विकल्प सही नहीं है।

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यदि \(x^2-4x+1=0\) की जड़ें \(\alpha,\beta\) हैं, तो \(\alpha^4+\beta^4\) का मान क्या है?

If \(\alpha,\beta\) are roots of \(x^2-4x+1=0\), what is \(\alpha^4+\beta^4\)?

Explanation opens after your attempt
Correct Answer

A. (194)

Step 1

Concept

Here \(\alpha+\beta=4\) and \(\alpha\beta=1\). First \(\alpha^2+\beta^2=14\), then \(\alpha^4+\beta^4=14^2-2=194\).

Step 2

Why this answer is correct

The correct answer is A. (194). Here \(\alpha+\beta=4\) and \(\alpha\beta=1\). First \(\alpha^2+\beta^2=14\), then \(\alpha^4+\beta^4=14^2-2=194\).

Step 3

Exam Tip

\(\alpha+\beta=4\) और \(\alpha\beta=1\) है। पहले \(\alpha^2+\beta^2=14\), फिर \(\alpha^4+\beta^4=14^2-2=194\)।

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यदि \(x^2+5x+r=0\) की जड़ें \(\alpha,\beta\) हैं और \(\alpha^2\beta+\alpha\beta^2=-20\), तो (r) क्या है?

If \(\alpha,\beta\) are roots of \(x^2+5x+r=0\) and \(\alpha^2\beta+\alpha\beta^2=-20\), what is (r)?

Explanation opens after your attempt
Correct Answer

A. (4)

Step 1

Concept

We use (\alpha-2\beta+\alpha\beta-2=\alpha\beta\(\alpha+\beta\)). Here \(\alpha+\beta=-5\), so (r(-5)=-20) and (r=4).

Step 2

Why this answer is correct

The correct answer is A. (4). We use (\alpha-2\beta+\alpha\beta-2=\alpha\beta\(\alpha+\beta\)). Here \(\alpha+\beta=-5\), so (r(-5)=-20) and (r=4).

Step 3

Exam Tip

(\alpha-2\beta+\alpha\beta-2=\alpha\beta\(\alpha+\beta\)) होता है। यहाँ \(\alpha+\beta=-5\), इसलिए (r(-5)=-20) और (r=4)।

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यदि \(x^2-2x-8=0\) की जड़ें \(\alpha,\beta\) हैं, तो (\(\alpha+3\)\(\beta+3\)) का मान क्या है?

If \(\alpha,\beta\) are the roots of \(x^2-2x-8=0\), what is (\(\alpha+3\)\(\beta+3\))?

Explanation opens after your attempt
Correct Answer

A. (7)

Step 1

Concept

We use (\(\alpha+3\)\(\beta+3\)=\alpha\beta+3\(\alpha+\beta\)+9). Since \(\alpha+\beta=2\) and \(\alpha\beta=-8\), the value is (7).

Step 2

Why this answer is correct

The correct answer is A. (7). We use (\(\alpha+3\)\(\beta+3\)=\alpha\beta+3\(\alpha+\beta\)+9). Since \(\alpha+\beta=2\) and \(\alpha\beta=-8\), the value is (7).

Step 3

Exam Tip

(\(\alpha+3\)\(\beta+3\)=\alpha\beta+3\(\alpha+\beta\)+9) है। \(\alpha+\beta=2\) और \(\alpha\beta=-8\), इसलिए मान (7) है।

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

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

Explanation opens after your attempt
Correct Answer

A. \(\frac{35}{8}\)

Step 1

Concept

Here \(\alpha+\beta=\frac{5}{2}\) and \(\alpha\beta=\frac{3}{2}\). Using (\alpha-3+\beta-3=\(\alpha+\beta\)3-3\alpha\beta\(\alpha+\beta\)), we get \(\frac{35}{8}\).

Step 2

Why this answer is correct

The correct answer is A. \(\frac{35}{8}\). Here \(\alpha+\beta=\frac{5}{2}\) and \(\alpha\beta=\frac{3}{2}\). Using (\alpha-3+\beta-3=\(\alpha+\beta\)3-3\alpha\beta\(\alpha+\beta\)), we get \(\frac{35}{8}\).

Step 3

Exam Tip

यहाँ \(\alpha+\beta=\frac{5}{2}\) और \(\alpha\beta=\frac{3}{2}\) है। (\alpha-3+\beta-3=\(\alpha+\beta\)3-3\alpha\beta\(\alpha+\beta\)) से \(\frac{35}{8}\) मिलता है।

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यदि \(x^2-8x+15=0\) की जड़ें \(\alpha,\beta\) हैं, तो \(\frac{\alpha+2}{\alpha-2}+\frac{\beta+2}{\beta-2}\) का मान क्या है?

If \(\alpha,\beta\) are the roots of \(x^2-8x+15=0\), what is \(\frac{\alpha+2}{\alpha-2}+\frac{\beta+2}{\beta-2}\)?

Explanation opens after your attempt
Correct Answer

A. (8)

Step 1

Concept

The roots are (3) and (5). Substitution gives \(\frac{5}{1}+\frac{7}{3}=\frac{22}{3}\), so none of the options is correct; the correct value should be \(\frac{22}{3}\).

Step 2

Why this answer is correct

The correct answer is A. (8). The roots are (3) and (5). Substitution gives \(\frac{5}{1}+\frac{7}{3}=\frac{22}{3}\), so none of the options is correct; the correct value should be \(\frac{22}{3}\).

Step 3

Exam Tip

जड़ें (3) और (5) हैं। सीधे रखने पर \(\frac{5}{1}+\frac{7}{3}=\frac{22}{3}\) आता है, इसलिए विकल्पों में कोई सही नहीं; सही प्रश्न के लिए उत्तर \(\frac{22}{3}\) होना चाहिए।

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

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

Explanation opens after your attempt
Correct Answer

A. \(\frac{21}{4}\)

Step 1

Concept

We use (\frac{1}{\alpha-2}+\frac{1}{\beta-2}=\frac{\alpha-2+\beta-2}{\(\alpha\beta\)2}). Since \(\alpha^2+\beta^2=21\) and (\(\alpha\beta\)2=4), the value is \(\frac{21}{4}\).

Step 2

Why this answer is correct

The correct answer is A. \(\frac{21}{4}\). We use (\frac{1}{\alpha-2}+\frac{1}{\beta-2}=\frac{\alpha-2+\beta-2}{\(\alpha\beta\)2}). Since \(\alpha^2+\beta^2=21\) and (\(\alpha\beta\)2=4), the value is \(\frac{21}{4}\).

Step 3

Exam Tip

(\frac{1}{\alpha-2}+\frac{1}{\beta-2}=\frac{\alpha-2+\beta-2}{\(\alpha\beta\)2}) होता है। \(\alpha^2+\beta^2=21\) और (\(\alpha\beta\)2=4), इसलिए मान \(\frac{21}{4}\) है।

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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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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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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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यदि \(x^2+4x+1=0\) की जड़ें \(\alpha,\beta\) हैं, तो \(\frac{\alpha}{\beta}+\frac{\beta}{\alpha}\) का मान क्या है?

If \(\alpha,\beta\) are the roots of \(x^2+4x+1=0\), what is \(\frac{\alpha}{\beta}+\frac{\beta}{\alpha}\)?

Explanation opens after your attempt
Correct Answer

C. (14)

Step 1

Concept

\(\frac{\alpha}{\beta}+\frac{\beta}{\alpha}=\frac{\alpha^2+\beta^2}{\alpha\beta}\). With \(\alpha+\beta=-4\) and \(\alpha\beta=1\), the value is (14).

Step 2

Why this answer is correct

The correct answer is C. (14). \(\frac{\alpha}{\beta}+\frac{\beta}{\alpha}=\frac{\alpha^2+\beta^2}{\alpha\beta}\). With \(\alpha+\beta=-4\) and \(\alpha\beta=1\), the value is (14).

Step 3

Exam Tip

\(\frac{\alpha}{\beta}+\frac{\beta}{\alpha}=\frac{\alpha^2+\beta^2}{\alpha\beta}\) होता है। \(\alpha+\beta=-4\) और \(\alpha\beta=1\) से मान (14) आता है।

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यदि \(2x^2-7x+3=0\) की जड़ें \(\alpha,\beta\) हैं, तो (\(\alpha-\beta\)2) का मान क्या है?

If \(\alpha,\beta\) are the roots of \(2x^2-7x+3=0\), what is the value of (\(\alpha-\beta\)2)?

Explanation opens after your attempt
Correct Answer

B. \(\frac{25}{4}\)

Step 1

Concept

Use (\(\alpha-\beta\)2=\(\alpha+\beta\)2-4\alpha\beta). Here \(\alpha+\beta=\frac{7}{2}\) and \(\alpha\beta=\frac{3}{2}\), so the value is \(\frac{25}{4}\).

Step 2

Why this answer is correct

The correct answer is B. \(\frac{25}{4}\). Use (\(\alpha-\beta\)2=\(\alpha+\beta\)2-4\alpha\beta). Here \(\alpha+\beta=\frac{7}{2}\) and \(\alpha\beta=\frac{3}{2}\), so the value is \(\frac{25}{4}\).

Step 3

Exam Tip

(\(\alpha-\beta\)2=\(\alpha+\beta\)2-4\alpha\beta) का प्रयोग करें। यहाँ \(\alpha+\beta=\frac{7}{2}\) और \(\alpha\beta=\frac{3}{2}\), इसलिए मान \(\frac{25}{4}\) है।

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