Question

Chapter 2: Polynomial
Section A(1 Mark)
Q1. If one root of the quadratic equation 2x2 + 2x + k = 0
en find the value of k.​

Answer 1

Correct Question:

If one root of the quadratic equation 2x² + 2x + k = 0  is 2. Find the value of k.​

Solution:

Given:

• One root of quadratic equation = 2.

To Find:

• Value of k.

It is given that 2 is the root of quadratic equation 2x² + 2x + k = 0,

∴ 2(2)² + 2(2) + k = 0

⇒ 2 × 4 + 4 + k = 0

⇒ 8 + 4 + k = 0

⇒ 12 + k = 0

⇒ k = -12.

Hence, k = -12.

Extra Info:

What is Quadratic Equation?

• A equation in the form ax² + bx + c = 0, where a, b and c are constants and a ≠ 0 is known as quadratic equation.

Answer 2

$\large \bold{\mathtt {\red{Correct \: Question}}}$

If one roots of the Quadratic equation 2x² + 2x+k=0 is 2. Find the value of k ?

$\large \bold{\mathtt {\red{Solution}}}$

$\implies2{x}^{2} + 2x + k = 0. \\ \\ \implies2{(2) }^{2} + 2(2) + k = 0. \\ \\ \implies 8 + 4 + k = 0. \\ \\ \implies12 + k = 0. \\ \\ \implies k = - 12.$

The Value of,

${ \red {\bold{{K = -12}}}}$