posted by Lucy X .
Hi, I need help with this question:
Use the addition and subtraction formulas ti fubd the exact values of the trigonometric ratios:
Okay, I'm just having trouble with a rather basic part of the question...
I wrote cos(pi/4 + pi/3), but now I realized that the trig ratio is negative. How do I write -7pi/12 as the sum/difference of two trig ratios?