Question

let θ(in radians) be an acute angle in a right triangle, and let x and y, respectively, be the lenghts of the sides adjacent and opposite θ. suppose also that both x and y vary with time
how are dθ/dt, dx/dt, and dy/dt related?

Answer 1

tan θ = y/x

sec²θ dθ/dt = 1/x dy/dt - y/x² dx/dt