
Jonathan T. answered 06/03/19
Calculus, Linear Algebra, and Differential Equations for College
d/dx y^n = ny^(n-1)y'
d/dx x^n = nx^(n-1)
When differentiating 'implicitly,' you gotta pay attention to the y's
So, for you question, we have
d/dx [ sin(ay) + cos(bx) = xy ]
implies cos(ay)d/dx(ay) - sin(bx)d/dx(bx) = xd/dxy + yd/dxx
implies ay'cos(ay) - bsin(bx) = xy' + y
Then solve for y. I will leave the rest for you to do. I made a video, but it got caught in limbo. Not sure if it will pop up or not...
JJ