00:01
So alpha is an angle in quadrant 1.
00:05
The cosine is 3 fifths, which means the adjacent side of that triangle is 3, and the hypotenuse is 5.
00:14
Can use pythagorean theorem to find that missing side.
00:20
So 9 plus a squared is 25.
00:24
A squared is 16, so a is just 4.
00:29
Okay.
00:31
So i'm going to need the tangent of this angle.
00:33
The tangent of alpha is opposite over adjacent.
00:38
I'm going to put a little circle around it so it's easy to find.
00:43
Now, beta is an angle in quadrant 4.
00:47
I have the sign ratio, so i have the opposite side over the hypotenuse...