Derivative of implicit function of equation y = sin (x + y)

Derivative of implicit function of equation y = sin (x + y)

Two sides of X are derived
y'=cos(X+y)×(1+y')=cos(x+y)+y'cos(x+y)
{1-cos(x+y)}y'=cos(x+y)
y'=cos(x+y)/{1-cos(x+y)}