Solve for y^1: 4[cos x × cos y × y^1 + sin y × (-sin x)]=0

Question

I need help please

Answer 1

Set the terms in brackets equal to zero, since any number times zero is always zero.

 

cos(x)cos(y)y - sin(x)sin(y) = 0

 

 

Add sin(x)sin(y) on both sides of the equation.

 

cos(x)cos(y)y = sin(x)sin(y)

 

 

Divide both sides of the equation by cos(x)cos(y).

 

y = [sin(x)sin(y)] / [cos(x)cos(y)]