The mathematical expression in question equals zero because the terms represent points in the complex plane that form the vertices of a regular polygon. Each point acts as a vector originating from the center, and the symmetry of the polygon ensures that these vectors sum to zero. This conclusion holds true unless a specific condition is met, where the variable c is a multiple of q/r, causing all vertices to converge at a single point. Understanding this geometric interpretation clarifies why the term evaluates to zero. The discussion effectively illustrates the relationship between complex numbers and geometric shapes in mathematics.