Question

Evaluate and simplify tan 15º.

Answer 1

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