Question

Use implicit differentiation to find dy/dx

x-tan(xy) = -5

What i don't understand is finding d/dx of -tan(xy), I think i should be getting dy/dx somehow, but using trig rules for derivatives, dtan(xy)/dx= sec^2(xy) can someone help?

Answer 1

When you take the derivative of -tan(xy) you have to account for the chain rule in the xy.

Explanation:

Your answer should be set up as such.

0 - sec^2(xy) ((y)+(x*dy/dx)) = 0

y + x*dy/dx = 0

dy/dx = -y/x