Question

tanx怎么展开为在x=π/4处的幂级数

Answer 1

tanx=x+x^3/3+2x^5/15+17x^7/315+62x^9/2835+...+[2^(2n)*(2^(2n)-1)*B(2n-1)*x^(2n-1)]/(2n)!+.(|x|