You don't have to, but it seems perfectly easy since you don't have to write anything down to solve it. c*sin(arctan(b/a)) gives b, and c*cos(arctan(b/a)) gives a. I'm not disputing that you can do it without, but I don't think it's necessarily any quicker or easier.
You don't have to, but it seems perfectly easy since you don't have to write anything down to solve it. c*sin(arctan(b/a)) gives b, and c*cos(arctan(b/a)) gives a. I'm not disputing that you can do it without, but I don't think it's necessarily any quicker or easier.
If it works it works. I just never would have thought to do it that way.