Step-by-step explanation:
cosec( 6b+ pie/8)=sec(2b-pie/8)
1/ sin( 6b +pie/8)=1/sec(2b-pie/8)
cos(2b-pie/8)=sin(6b-pie/8)
cosX =sin(pie/2-x)
sin(pie/2-2b+pie/8)=sin(6b+pie/8)
pie/2-2b+pie/8=6b+pie/8
pie/2=8b
b = pie/16