1. The problem statement, all variables and given/known data If cos x = a/b and tan x = c/d; where a, b, c do not equal 0, then sin x is..... (a) bd/ac (b) bc/ad (c) ad/bc (d) ad/bc 2. Relevant equations 3. The attempt at a solution The way I see it, if cos x = a/b, then b=hypotenuse. if tan x = c/d, then d= hypotenuse (two hypotenuse values?) and c = opposite. Therefore sin x = c/d. I don't know why the answers in the book use products of the vairables in their numerators and denominators. Please help. Much thanks in advance.