If cos(pi*n) = (-1)^n is cos(-pi*n) = (-1)^n

[mrmerchant786]

Homework Statement

i wassolving a Fourier series integral, and needed some help
if cos(pi*n) = (-1)^n is cos(-pi*n) = (-1)^n ?

Homework Equations

i think it is because cos is an even function so -x of the function should still remain the same, because if you look at the graph and flip it its still the same graph

if someone could reply to confirm my thoughts or tell me why its wrong, that would be great thanks :)

The Attempt at a Solution

 

[Buffu]

Homework Statement

i wassolving a Fourier series integral, and needed some help
if cos(pi*n) = (-1)^n is cos(-pi*n) = (-1)^n ?

Homework Equations

i think it is because cos is an even function so -x of the function should still remain the same, because if you look at the graph and flip it its still the same graph

if someone could reply to confirm my thoughts or tell me why its wrong, that would be great thanks :)

The Attempt at a Solution

you are correct because $\cos (x) = \cos (-x)$.

 

[mrmerchant786]

you are correct because $\cos (x) = \cos (-x)$.

thanks , thought so