#### neptune

##### Member

I was studying Taylor's series,

Question 1: but i don't know how they got the formula for Taylor series

books always starts with the power series of

but why ?

Definition :"

**Taylor's theorem**gives an approximation of a

*k*-times differentiable function around a given point by a

*k*-th order

**Taylor polynomial**. " (source - wikipedia)

Question 2: what is k times differentiable.