1. The problem statement, all variables and given/known data I'm having a bit of trouble with this Maclaurin Series question. It should be simple enough but I can't get the answer which is given as x2. It's been a while since i've done series and my being rusty is a little annoying. Hopefully someone can help :) Consider: f(x)=x*sin(x) Question asks to find the Quadratic Maclaurin Polynomial for f(x). So this is what I did. First I got the nth derivatives: f1(x) = x*cos(x) + sin(x) f2(x) = -x*sin(x) + cos(x) + sin(x) P2(x): 0 + x*0 + (x^2)(0 + 1 + 0)*(1/2!) = x2/2 I'm sure i'm doing something blatantly wrong here but I can't seem to work it out. Fresh eyes might be useful :) Thanks a lot.