Question

Write the polar equation r = cos(4*theta) in the parametric form x = x(t), y = y(t)

Answer 1

multiply both sides by r
r^2 = 4 cos (4theta)
r^2 = 8cos^4 ( theta) - 8 cos^2(theta) + 1

Answer 2

x^2+y^2 = 8 ( x/r)^4 - 8(x/r)^2 + 1