(a) Use Exercise 81 to show that the angle between the tangent line and the radial line is ψ = π/4 at every point on the curve r = e6.
(b) Illustrate part (a) by graphing the curve and the tangent lines at the points where θ = 0 and π/2.
(c) Prove that any polar curve r = f (θ) with the property that the angle ψ between the radial line and the tangent line is a constant must be of the form r = Cek6, where C and are constants.