Find dydx if y=12(1−cos t),x=10(t−sin t),−πx<t<π2.
Given, y=12(1−cos t),x=10(t−sin t)
Differentiating both equations w.r.t. t, we get
∴ dydt=12(0+sin t) and dxdt=10(1−cos t)dydx=dydtdxdt=dydt×dtdx=12 sin t10(1−cos t)=12×2 sin (t/2)cos (t/2)10{2 sin2(t/2)}=65cot(t2) (∴ sin t=2 sin t2 cos tx and cos t=1−2sin2t2)