Question

which is not a quadratic equation in x? a) 3x^2 + 2x - 1 = 0 b) 3x^2 - 36 = 0 c) ax^2 + bx + c = 0 d) 3x^3 - 2x^2 + 1 = 0

Answer 1

d) 3x^3 - 2x^2 + 1 = 0

Explanation:

Option (d) 3x^3 - 2x^2 + 1 = 0 is not a quadratic equation in x.

A quadratic equation is a polynomial equation of degree 2 in one variable. In other words, the highest power of the variable in a quadratic equation is 2.

Option (d) has a highest power of x as 3, so it is not a quadratic equation. It is a cubic equation.

On the other hand, options (a), (b), and (c) are all quadratic equations in x.