00:01
We want to know the sine, cosine, tangent, cosecant, secant, and cotangent of each one of these.
00:10
So let's just start with sine and cosine.
00:12
Let's look at a graph.
00:14
When i look at negative pi, we're actually looking here on the negative x -axis.
00:20
Well, when we look at the sine, that's going to be zero here.
00:24
Cosine is going to be negative one.
00:27
So now we think sine over cosine is tangent, that's going to be zero.
00:30
Reciprocal of zero is undefined.
00:33
Reciprocal of negative one is negative one.
00:36
Reciprocal of zero is undefined.
00:39
Now let's get down to zero.
00:40
Zero is going to be on the positive, if i'm going to do that in blue, positive x -axis...