Hello, I have a data set that follows an equation similar to sin(x)+x. Just from eyeballing the data, it seems like there should be a pretty simple trigonometric function A*sin(B*x)+C*x. I went to school for engineering so I have some basic/intermediate knowledge of mathematics but it's been a while since I've applied it. Is there any software (freeware or Excel) that I can use? How about any cool math tricks? Thanks!