Prove that? cot 15^@ = 2+ sqrt3

1 Answer
May 20, 2018

cot15

=cot(45-30)

=(cot45cot30+1)/(cot30-cot45)

=(1*sqrt3+1)/(sqrt3-1)

=(sqrt3+1)^2/((sqrt3-1)(sqrt3+1))

=(3+1+2sqrt3)/(3-1)

=(4+2sqrt3)/2

=2+sqrt3