xcos(a+y)=cosy,
If x cos(a+y) = cos y, then prove that dydx=cos2(a+y)sina
Hence show that sin a d2ydx2+sin2(a+y)dydx=0
OR Find dydx if y=sin−1[6x−4√1−4x25].
If cos y=x cos (a+y),with cos a≠1,prove that dydx=cos2(a+y)sin a.