00:01
So define our linear approximations, so we can compare them to the actual values of tangent.
00:07
We first need to fill everything out in this equation here, where a is the center, and in this case, it tells a is zero.
00:15
So i'm just going to go ahead and plug those in over here really quickly.
00:20
And that's going to simplify this down to f of 0 plus f prime of 0, and then that would just be times x.
00:28
So let's come over here and first find f of 0.
00:32
Well, f is tangent.
00:35
So f of 0 is going to be tangent of 0.
00:39
And tangent is sine over cosine, which would be 0 over 1, so that's just going to be 0.
00:44
Now we need to find the derivative.
00:48
And so the derivative of tangent should be secant squared.
00:57
And sikin is just 1 over cosine.
01:03
So plug it in 0 into here, so f prime of 0 is going to just be 1, because it would be 1 over 1 squared and that would just be 1.
01:16
So now we can come over here and plug all this in.
01:18
So l of x, our linear approximation, close to 0 is going to be, well, f of 0 is 0, f prime of 0 is 1, which is just going to leave us with x.
01:34
So now let's go ahead and plug in those values.
01:37
So we had, let's see, so for the x values, i believe it was 0 .01, 0 .1, and then just 1.
01:51
And then l of x, well, l of x, we already said it's just x.
01:56
So plugging those in would be 0 .01, 0 .1, and 1...