that is the method which is in my book, but i know there is a short cut method with odd and even. using that method above you need to do the equation for each function value which means using it multiple times and i always end up getting it wrong coz the equation is so long and messy.
i dont think it explains the odd and even method though, but im not sure coz i dont understand most of it :)
could someone explain it in simple terms to me?