Which of the following is an even function?

f (x) = |x|

f (x) = x3 - 1

f (x) = - 3x

f (x) = RootIndex 3 StartRoot x EndRoot

Answer: f (x) = |x|

Step-by-step explanation:

A function is even if for every real N, f (N) = f (-N)

As you know, the module of a function always returns the positive value of a number, so I-3I = 3 = I3I (and that for every number)

So the function f (x) = IxI is an even function.

Functions with odd powers can not be even functions, so the second and tird options are discarded.

the fourth functions seems to be:

f (x) = ∛x = (x) 1/3 which is not even, because if x = 1, f (1) = 1, and if x=-1, f (-1) = - 1

f (x) = |x| that's the answer