Prove that this is true for every n. (n is an element of natural numbers)
cos(n*pi) = (-1)^n
I would very much appreciate your help, thank you.
Prove that this is true for every n. (n is an element of natural numbers)
cos(n*pi) = (-1)^n
I would very much appreciate your help, thank you.
$\displaystyle \text{Use: } \cos((n+1) \pi ) = \cos(n\pi + \pi) = \cos(n\pi)\cos(\pi) - \sin(n\pi)\sin(\pi), \text{ and continue on from there.}$