I need some major help with some dot products. I was curious if when getting the dot product, you add the angles of each one to each other. I'll give the problem: theta=(/) Find A*B(dot product) A=8.6i+5j B=9.7i+2.6j So i used the formula my teacher gave me to find the angle, theta, tan(/)=y/x. So i got the Angle for each: tan(/)=5/8.6 (/)=tan^-1(5/8.6) (/)=30.2 and then for B: tan(/)=2.6/9.7 (/)=tan^-1(2.6/9.7) (/)=15 So now, I am given two formulas to get the dot product A*B=ABcos(/) AB means the magnitude of A multiplied by the magnitude of B. I can get that, but it asks for one angle... what do I do? Add the two angles together? Or subtract them? I'm confused, please help!