Given that
f(x)= x^3 i f x≥0
x i f x<0
which of the following functions is even?
I. f(x)
II. f(|x|)
III. |f(x)|
f(x) is not even, since
f(-x) ≠ f(x) for x≠0,1
f(3) = 27
f(-3) = -3
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f(|x|) is even since |x| is always positive
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|f(x)| is not even, again, because x ≠ x^3 for x≠0,1
|f(3)| = 27
|f(-3)| = 3