Question

(9sin168)/(cos84*cos6)

Answer 1

$frac{9sin168}{cos84*cos6}= frac{9sin(2*84)}{cos84*cos6}= frac{9*2sin84*cos84}{cos84*cos6}= frac{18sin84}{cos6}= frac{18sin84}{cos(90-84)}=\\= frac{18sin84}{sin84} =18$