Question

Which of the following it’s an even function? F(x)=|x|
f(x)=x^3-1
f(x)=-3x

Answer 1

f(x) = IxI

Explanation:

Answer 2

f(x) = |x|

Explanation:

A function f(x) is called even function,

If f(-x) = f(x),

In first option

`f(x)=|x|`

Since, f(-x) = |-x| = |x| = f(x)

⇒ f(x) is an even function,

In second option,

`f(x)=x^3-1`

`f(-x)=(-x)^3-1 = -x^3 - 1\\eq f(x)`

⇒ f(x) is not an even function,

In third option,

`f(x)=-3x`

`f(-x)=-3(-x)=3x\\eq f(x)`

⇒ f(x) is not an even function.