Question

Differentiate x^2+y^2=25?

Answer 1

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/dx`s.
`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!