1/1-x
Sum from 0-infinity of x^n =1+x+x^2+x^3
R=1
e^x
Sum from 0-infinity of x^n/n!=1+x/1!+x^2/2!+x^3/3!
R=infinity
sinx
Sum from 0-infinity of (-1)^n*x^2n+1/(2n+1)!=x-x/3!+x^5/5!
R=infinity
cosx
Sum from 0-infinity of (-1)^n*x^2n/(2n)!=1-x^2/2!+x^4/4!-x^6/6!
R=infinity
arctanx
Sum from 0-infinity of (-1)^n*x^2n+1/2n+1=x-x^3/3+x^5/5
R=1
ln(1+x)
Sum from 1 to infinity of (-1)^n-1*x^n/n=x-x^2/2+x^3/3-x^4/4
R=1
(1+x)^k
Sum from 0 to infinity of (k n)x^n=1+kk+k(k-1)/2!x^2+k(k-1)(k-2)/3!*x^3
R=1