00:01
Okay, so we want to find the equation of our tangent line.
00:05
So let's note that we're given our function and our points, and this equation here is what we'll use to find our slope.
00:13
So let's start by finding our slope.
00:15
So we're going to find f prime evaluated at our x point, which is negative 1.
00:20
So that's negative 1.
00:22
So that's equal to the limit as x approaches negative 1.
00:29
So that's we have f of x, so that's x squared plus 2, and now we want to subtract our function evaluated at negative 1.
00:38
So that's negative 1 squared.
00:40
So that gives me a 1 plus a 2, so we get a 3, all over x minus a negative 1.
00:48
So that's plus 1.
00:49
Okay, so let's simplify what we have in our numerator.
00:53
So we get x squared, and then we have a minus 1.
00:57
So notice that this here is the difference of 2 squares.
01:00
So we can actually factor that into an x minus 1.
01:06
Times an x plus 1, all over x plus 1...