00:01
Okay, so we want to find the equation of our tangent line, given our x value.
00:06
So to find our tangent line, we're going to need to use point slope form.
00:11
So we're going to need a point on our line as well as our slope, and we can find our slope by using this equation here.
00:18
And we're also given our x points, so let's find our corresponding y value.
00:22
So that's going to be, well, let's note that f of a.
00:31
Well our a value is what's given for x.
00:34
So this is going to be negative 1.
00:37
So here we have f of negative 1.
00:41
So that's equal to 6 minus 1, which is equal to 5.
00:47
And so our point on our line, that is x1, y1, that's equal to negative 1 .5.
00:58
And let's find a rolling slope.
01:01
So m is equal to the limit as x approaches negative 1 of f of x that's 6 minus x squared minus f of a all over x minus a.
01:15
So that's x minus negative.
01:17
So that's plus 1...