Hello Everyone, I was just wondering if there was a way to add two vectors that are determined by spherical coordinates (radius, theta, phi). For example, if I have v1 = (5, Pi/4, Pi/2) and v2 = (3, Pi, -Pi/2) is there a way to add these using their respective radii, thetas, and phis or do I HAVE to convert them to Cartesian coordinates first, perform the addition, and then convert back? Also, if anybody knows, what is the difference between "bound" and "free" vectors? I was looking around and this came up but the description was a bit fuzzy. Thanks again!