First question - do you know the sum and difference formulas?
Hello, eh501!
Okay, you know the three formulas:
. .
To use those formulas, we need more trig values.If , and and are positive acute angles, find
. .
We can use: .
Since
. . . .
Then: .
. . Hence, we have: .
Use the same procedure on to find
. . then you can use those formulas . . .