Question

If x = 2 cos t - cos 2t and y = 2 sin t - sin 2t, find dy/dx at t = pi/4​

Answer 1

x = 2 cos t - cos 2t

y = 2 sin t - sin 2t

dx/dt = - 2sin t + 2 sin 2t

dy/dt = 2cos t - 2 cos 2t

(dy/dt) /(dx/dt) = dy/dx = ( 2 cos t - 2 cos 2t ) / ( - 2 sin t + 2 sin 2t )