00:01
Hi everyone, so today we're looking at problem number two in the textbook where we are finding if tangent of 2 theta is equal to sine of 2 theta over cosine of 2 theta.
00:10
We'll be using these identities over here, which are also in the textbook.
00:16
So we can start off by saying that the sign of 2 theta divided by the cosine of 2 theta is equal to 2 sine theta, divided by cosine squared theta minus sine squared theta.
00:26
Nothing fancy just using these identities above.
00:29
Now, an interesting step we can take here is to factor out cosine squared from the top and the bottom.
00:36
So from the top, if we take out a cosine squared, what's remaining is the 2 -sign theta divided by cosine theta.
00:51
And on the bottom, if we take out a cosine squared, what's remaining is 1 minus sine squared theta over cosine -squared.
01:04
And we continue just by simplifying that equation, what we'll get is these two cosine squareds will cancel out...