00:01
So i have x squared plus y squared, and that's equal to 32.
00:12
So i'm going to take the derivative with respect to x of both sides.
00:19
It's going to give me 2x.
00:21
That'll be dx, dx, plus 2y, d, d, y, dx, equal to zero.
00:29
So dx, dx, dx is just one.
00:34
I'm going to subtract negative 2x from both sides.
00:40
So 2y, d, y, d, x equals negative 2x.
00:45
I'm going to divide both sides by 2y.
00:49
So d, y, dx is going to equal negative x over y.
00:54
I want to find the equation of the tangent line at the point negative 4 positive, sorry, 4 negative...