Question

test the convergence for cos npi

Answer 1

Find the values of
\[
\cos(n \pi), \text { for } n=1,23,4,5,6,
\]
and see what you can deduce

Answer 2

1,2,3

Answer 3

\[
\cos( \pi) = -1\\
\cos( 2 \pi) = 1\\
\cos( 3 \pi) = -1\\
\cos( 4\pi) = 1\\
\cos( 5\pi) = -1\\
\]

Answer 4

What can you deduce?

Answer 5

you can not reduce anything now you are finished

Answer 6

If n is odd the \( \cos(n \pi)\)=-1
If n is even the \( \cos(n \pi)\)=1
So the sequence is not convergent