Question

Which represents a quadratic function? f(x) = −8x3 − 16x2 − 4x f (x) = x 2 + 2x − 5 f(x) = + 1 f(x) = 0x2 − 9x + 7

Answer 1

we know, any equation is in the form ax² + bx + c , where a , b , c belongs to all real numbers and a ≠ 0 is know as quadratic expression. and f(x) = ax² + bx + c is said quadratic function.

Let's check all options :

(a) f(x) = -8x³ - 16x² - 4x
this is not a quadratic function because maximum power of x should be 2.

(b) f(x) = x² + 2x - 5
this is quadratic function because it follows the condition to be quadratic.

(c) f(x) = +1
it is constant function. of course it is not a quadratic function.

(d) f(x) = 0.x² -9x + 7
it is not a quadratic function because coefficient of x² = 0.

hence, option (b) is correct.

Answer 2

We know, any condition is in the frame ax² + bx + c,

where a , b , c has a place with every genuine number and a ≠ 0 is known as quadratic articulation. what's more, f(x) = ax² + bx + c is said quadratic capacity.

How about we check all choices:

(a) f(x) = - 8x³ - 16x² - 4x this is certifiably not a quadratic capacity since most extreme intensity of x ought to be 2.

(b) f(x) = x² + 2x - 5 this is quadratic capacity since it takes after the condition to be quadratic.