Differentiate x^2+y^2=25?

1 Answer
Sep 15, 2017

The answer is dy/dx =-x/y

Explanation:

Use chain rule on the left side and a derivative of a constant is 0.
2xdx+2ydy=0
Divide both sides by dx.
2x+2ydy/dx=0
Isolate the dy/dxs.
2ydy/dx=-2x
Divide both sides by 2y to have only the dy/dx on one side.
dy/dx = -2x/2y
Simplify.
dy/dx= -x/y
And you're done!