Question

if sinA = 8/17 and sinB = 5/13 , Aand B are acute angel , show that sin ( A + B ) =171/221

Answer 1

hey friend here is your answer
first we find value of cosA and cosB
then value of cosA=15/17 &cosB=12/13
LHS,sin(A+B)=sinAcosB+cosAsinB

putting value
8/17×12/13+15/17×5/13
on solving
sin(A+ B)=171/221