- #1
kala
- 21
- 0
Homework Statement
how could i prove that cos x= sum (n=1 to 00) [((-1)^n) * x^(2n)/((2n)!)]
is continuous and differentiable at each x in R
Homework Equations
the Taylor Expansion of cosine is the given equation
The Attempt at a Solution
basically i need to prove that the Taylor expansion of cos is differentiable and continuous. I think i need to use the Weierstrass M-test, however i could not figure out what M_n was, is there a different way to go about this one, or any suggestions for M_n