00:02
I want to find the tangent of a plus b.
00:08
That formula says to take the tangent of the first angle, add to it the tangent of the second angle, divide that by the difference 1 minus tan a, tan b.
00:22
So you can see from the formula i need the tangent of each of these angles.
00:29
A is in quadrant 2, and i have the sign, so i have 3.
00:35
The opposite side and the hypotenuse.
00:38
I'm going to solve for the adjacent side using the pythagorean theorem.
00:45
So a squared is going to equal 45.
00:49
A is the square root of 45, which simplifies three radical five.
00:57
So the tangent of a is going to be opposite, which is two over adjacent, three rad five, and it's negative in quadrant two.
01:09
Let's do the same thing with b.
01:12
B is in quadrant 1.
01:15
Cosine is adjacent over hypotenuse.
01:19
So a squared plus 2 squared equals 3 squared.
01:26
A squared is 5.
01:28
A is the square root of 5.
01:31
Tangent of b is opposite over adjacent, positive in quadrant 1...