# Thread: finding a magnitude in a non-orthonormal coordinate system

1. ## finding a magnitude in a non-orthonormal coordinate system

Hi everyone, Attached is a diagram showing the problem and my work. I'm trying to find the magnitude of my vector in order to be able to get it in a x-y coordinate form. So far I haven't had any luck, with some magnitudes coming out to be negative! I don't know what I'm doing wrong, but obviously it's something big.

Known, but arbitrary: $\displaystyle$\theta _1$,$\theta _2$,$v_x$,$v_y$$. I need \displaystyle magnitude(V) (or) v_E$$, and $\displaystyle$v_N