Question

Which represents a quadratic function?

A)f(x) = −8x3 − 16x2 − 4x

B)f (x) = x 2 + 2x − 5

C)f(x) = + 1

D) f(x) = 0x2 − 9x + 7

Answer 1

b. x^2 +2x-5 is a square and basically a quadratic function

Answer 2

B) f (x) = x² + 2x − 5 is quadratic function .

Explanation:

Given : Functions .

To find : Which represents a quadratic function.

Solution : We have given functions .

Quadratic function in form of ax² + bx + c = 0 which has degree 2.

Then we can see f (x) = x² + 2x − 5 inform of quadratic function .

Where , a = 1 ,b =2 ,c = -5.

Option D also has degree 2 but its coefficient of x² is 0. so, we will not consider it.

Therefore, B) f (x) = x² + 2x − 5 is quadratic function .