00:01
The directions say to use the figure to find the exact value of the following trigonometric function.
00:08
And the trigonometric function is tangent of 2 theta.
00:11
So let me write that down.
00:17
Now i'm going to show you how i approach it.
00:20
All right now tangent of 2 theta is sine 2 theta divided by cosine 2 theta.
00:32
Now sine of 2 theta is 2 sine theta times cosine theta.
00:41
And then cosine of 2 theta there's a couple ways you can go.
00:47
But i'm going to say this is 2 cosine squared theta minus 1.
00:55
That's what cosine of 2 theta equals.
00:57
Now we're ready to put in our values.
01:02
Now this is 2 times sine of theta is opposite over hypotenuse.
01:08
And so that's 15 divided by 17 times cosine of theta which is adjacent over hypotenuse.
01:16
That's 8 divided by 17.
01:21
Now the denominator is 2 times cosine of theta is 8 over 17...