The derivative y'of implicit function y = y (x) determined by equation y = 3x ln (x + y) + siny

The derivative y'of implicit function y = y (x) determined by equation y = 3x ln (x + y) + siny

Derivation on both sides of the equation: y '= 3 - (1 + y') / (x + y) + y'cosy
∴y'=[3(x+y)-1]/[(x+y)(1-cosy)+1]