Question

How to solve tan 165 using the sum and difference formula?

Answer 1

well, the trick is picking a pair of numbers whose sum or difference is 165, and whose values you can readily compute. Looking at the unit circle, you probably can readily compute the values for 0, 30, 45, 60, 90, 120, 135, 150, 180, right? Pick a pair of them that you can use in either the sum or difference formula to get the answer.

Answer 2

i guess i will use the sum

Answer 3

that's how I did it...

Answer 4

ok so i guess i will use 120 and 45

Answer 5

yes, that should do it for you