Forming New Equations MCQ Quiz - Objective Question with Answer for Forming New Equations - Download Free PDF

Last updated on Apr 11, 2025

Latest Forming New Equations MCQ Objective Questions

Forming New Equations Question 1:

If α, β are the roots of 6x+ 13x + 7 = 0, then the equation whose roots are α2, β2 is:

  1. 36x2 -  87x + 49 = 0
  2. 36x2 -  85x + 49 = 0
  3. 36x2 -  85x - 49 = 0
  4. 36x2 +  87x - 49 = 0

Answer (Detailed Solution Below)

Option 2 : 36x2 -  85x + 49 = 0

Forming New Equations Question 1 Detailed Solution

Given:

6x2 + 13x + 7 = 0

Concept used:

We know that a quadratic equation whose roots are α and β is given by x2 - (α + β) x + αβ = 0

Calculation:

6x2 + 13x + 7 = 0

⇒ x2 + 13x/6 + 7/6 = 0

So, (α + β) = - (13/6)

αβ = 7/6

Now,

(α + β)2 = α2 + β2 + 2αβ

⇒ 169/36 = α2 + β2 + 7/3

 169/36 - 7/3 = α2 + β2

 (169 - 84)/36 = α2 + β2

 85/36 = α2 + β2

Now,

x2 - (α2 + β2)x + α2β2 = 0

⇒ x2 - 85/36x + 49/36 = 0

⇒ 36x2 - 85x + 49 = 0

∴ The required answer is 36x2 - 85x + 49 = 0.

Top Forming New Equations MCQ Objective Questions

If α, β are the roots of 6x+ 13x + 7 = 0, then the equation whose roots are α2, β2 is:

  1. 36x2 -  87x + 49 = 0
  2. 36x2 -  85x + 49 = 0
  3. 36x2 -  85x - 49 = 0
  4. 36x2 +  87x - 49 = 0

Answer (Detailed Solution Below)

Option 2 : 36x2 -  85x + 49 = 0

Forming New Equations Question 2 Detailed Solution

Download Solution PDF

Given:

6x2 + 13x + 7 = 0

Concept used:

We know that a quadratic equation whose roots are α and β is given by x2 - (α + β) x + αβ = 0

Calculation:

6x2 + 13x + 7 = 0

⇒ x2 + 13x/6 + 7/6 = 0

So, (α + β) = - (13/6)

αβ = 7/6

Now,

(α + β)2 = α2 + β2 + 2αβ

⇒ 169/36 = α2 + β2 + 7/3

 169/36 - 7/3 = α2 + β2

 (169 - 84)/36 = α2 + β2

 85/36 = α2 + β2

Now,

x2 - (α2 + β2)x + α2β2 = 0

⇒ x2 - 85/36x + 49/36 = 0

⇒ 36x2 - 85x + 49 = 0

∴ The required answer is 36x2 - 85x + 49 = 0.

Forming New Equations Question 3:

If α, β are the roots of 6x+ 13x + 7 = 0, then the equation whose roots are α2, β2 is:

  1. 36x2 -  87x + 49 = 0
  2. 36x2 -  85x + 49 = 0
  3. 36x2 -  85x - 49 = 0
  4. 36x2 +  87x - 49 = 0

Answer (Detailed Solution Below)

Option 2 : 36x2 -  85x + 49 = 0

Forming New Equations Question 3 Detailed Solution

Given:

6x2 + 13x + 7 = 0

Concept used:

We know that a quadratic equation whose roots are α and β is given by x2 - (α + β) x + αβ = 0

Calculation:

6x2 + 13x + 7 = 0

⇒ x2 + 13x/6 + 7/6 = 0

So, (α + β) = - (13/6)

αβ = 7/6

Now,

(α + β)2 = α2 + β2 + 2αβ

⇒ 169/36 = α2 + β2 + 7/3

 169/36 - 7/3 = α2 + β2

 (169 - 84)/36 = α2 + β2

 85/36 = α2 + β2

Now,

x2 - (α2 + β2)x + α2β2 = 0

⇒ x2 - 85/36x + 49/36 = 0

⇒ 36x2 - 85x + 49 = 0

∴ The required answer is 36x2 - 85x + 49 = 0.

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