I'm Billy,
Question: How to eliminate t? Billy Hi Billy,You can solve the second equation for cost, cost = 1  y/r and then t is the inverse cosine of 1  y/r. Substitute this into the first equation for the first t and then express sint using the fact that sin^{2}t + cos^{2}t = 1. The parametric form is much easier to work with. Harley
