Angles A and B are located in the first quadrant. If sin a =5/13 and cos b= 3/5 , determine the exact value of cos (a+b) .

Question

​Angles A and B are located in the first quadrant. If sin a =5/13 and cos b= 3/5 , determine the exact value of cos (a+b) .

Steve · Answer

well, we have cosa = 12/13 sinb = 4/5 So, just plug them into cos(a+b) = cosa cosb - sina sinb

Hyde · Answer

I got the answer .22882 is that correct?

​Angles A and B are located in the first quadrant. If sin a =5/13 and cos b= 3/5 , determine the exact value of cos (a+b) .