If A and B are two angles in standard position in Quadrant I, find cos(A + B) for the given function values.
sin A = 8/17 and cos B = 12/13
+36916 Q I sin and cos are both positive
Usung cos^2 + sin ^2 = 1 you will find cos a = + 25/17
and sin b = + 5 /13
Now use this trig identity:
cos (a+b) = cos a cos b - sin a sin b for your answer......... 
