Question

suppose we approximate the function f(x)=cos(x) by series. Calculate the truncation error

Answer 1

Am I safe to assume you're finding the truncation error at zero?

Answer 2

\[hint : \cos (x) = 1 - \frac{ x^2 }{ 2! }+\frac{ x^4 }{4! } +...... + (-1)^n \frac{ x^(2n) }{ 2n! }\]