Question

(9sin 11*sin79)/sin 22

Answer 1

$frac{9sin11*sin79}{sin22}= frac{9sin11*sin(90-11)}{sin(2*11)}=frac{9sin11*cos11}{2sin11*cos11} = frac{9}{2}=4,5$

Answer 2

$cfrac{9sin 11sin79}{sin22} = cfrac{9sin 11sin(90-11)}{sin(2cdot11)} =cfrac{9sin 11cos11}{2sin11cos11} =cfrac{9}{2} =4.5$