00:01
Okay, so for this problem, we're going to differentiate, sorry, take the integral of tangent of x, dx.
00:06
We cannot forget that.
00:06
And we're actually going to rewrite this as a sign of x times 1 over cosine of x, dx.
00:14
And we're going to set our u equal to cosine of x.
00:21
So our du is equal to negative sine of x, dx.
00:25
And the metric is perfectly here if we just have it.
00:27
Now we're going to rewrite our integral as negative 1.
00:32
Over u, d u, and now we can have the negative natural log of u plus c, and we could actually rewrite this as a negative natural log of you, which is cosine of x...