Evaluate and simplify tan 15º.
tan(15) = tan(45 - 30) = [tan(45) - tan(30) ] / [ 1 + tan(30)tan(45)] = (1 - 1/sqrt(3)) /(1 + 1/sqrt(3)) = (sqrt(3) - 1)/(sqrt(3) + 1) = (sqrt(3) - 1)^2 /(3 - 1) = 1/2 [3 + 1 - 2sqrt(3) ] = (2 - sqrt(3) )= 0.27 is your answer
