Question

If A+B=90‰ and Dec A=15/3 ,find the value of covsc B.

Answer 1

$a + b = 90 \\ putting \: the value \: of \: a \: in \: eq \: 1 \\ 15 l2 + b = 90 \\ b = 90 - 15l2 \\ b = 8.25ans$