Question

find acute angle A and B if (a+2b) =√3/2 and cos (a+4b)=0

Answer 1

sin(A + 2B)=root3/2 and cos(A +4B)=0
i.e. A+2B = 60 degrees and A + 4B = 90 degrees
Solve for A and B , you will get A = 30 degrees and B = 15 degrees