Question

Give an example of an even function and explain algebraically why it is even.

Answer 1

`f(x)=(x^2)/(\cos x)\\\\ f(-x)=((-x)^2)/(\cos (-x))=(x^2)/(\cos x)`

It's even, because
`f(x)=f(-x)`

Answer 2

y=x^4+4
it's an even function b/c if you input (-x) for x, f(x) would remain the same.

y=(-x)^4+4
y=x^4+4