Question

tan15度减1分之tan15度加1等于多少？

求高手

Answer 1

(1+tan15)/(tan15-1)
=-(tan45+tan15)/(1-tan45tan15)
=-tan(45+15)
=-tan60
=-√3.
希望采纳谢谢！

Answer 2

(tan15+1)/(tan15-1) =(tan15)^2-1=(sin15/cos15)^2-1=(sin(45-30)/cos(45-30))^2-1=(sin45cos30-cos45sin30)^2/(cos45cos30+sin45sin30)^2 -1=(√2/2*√3/2-√2/2*1/2)^2/(√2/2*√3/2+√2/2*1/2)^2-1=((√6-√2)/4)/(√6+√2)/4）^2-1=（√6-√2/√6+√2）^2-1=(2-√3)^2-1=6-4√3

Answer 3

tan15°=sin15°/cos15°=sin(45°-30°)/cos(45°-30°)=(√6-√2)/(√6+√2)
代入原式很容易算出=-√3

Answer 4

1-2*根号3