Question

consider the equation kx2+2x=c(2x2+b) for the equation to be quadratic which of these cannot be the value of k​

Answer 1

Given info : considering the equation kx² + 2x = c(2x² + b)

To find : for the equation to be quadratic find the condition for k.

Solution : here equation is .. kx² + 2x = c(2x² + b)

⇒kx² + 2x = 2cx² + bc

⇒kx² - 2cx² + 2x - bc = 0

⇒(k - 2c)x² + 2x - bc = 0......(1)

this is the form of quadratic equation Ax² + Bx + C = 0.

But we know, coefficient of x² ≠ 0 in quadratic equation.

so, coefficient of x² of equation (1) = (k - 2c) ≠ 0

⇒k ≠ 2c

Therefore the value of k cannot be 2c

Answer 2

kx^2+2x = 2cx^2+bc

kx^2-2cx^2+2x-bc=0

(k-2c)x^2 + 2x-bc

We know that In General form of quadratic equation x^2 value should not equal to 0

Hence k-2c is not equal to 0