Question

tan15度等于几分之几

Answer 1

tan15°

=tan(60°-45°)

=(tan60°- tan45°)/(1+ tan60°*tan45°)

=(根号3 -1)/(1+根号3）

=(根号3-1)*(根号3-1)/[(根号3+1)(根号3-1)]

=(4-2根号3)/2

=2-根号3