Use polynomial division.
Expand {x-x^3/3!}/{1-x^2/2}. The first two terms is your answer.
My problem is....
Use the series expansions for sin x and cos x to find the first two
terms of a series expansion for tan x
but which series do i use? Power, maclaurin?
also how do I find tan x ( i know sinx/cosx=tanx) but how do i get there using series?
many thanks
You should learn the polynomial long division method. Please refer, Polynomial Long Division. I hope you will find it simple and illustrative.