Question

已知tan(a+派/12)=2则tan(a+派/3)的值为?

急需解决..

Answer 1

解：
可设x=a+(π/12)
则a+(π/3)=x+(π/4)且tanx=2
∴tan[a+(π/3)]
=tan[x+(π/4)]
=[tanx+tan(π/4)]/[1-tanxtan(π/4)]
=(2+1)/(1-2)
=-3

Answer 2

tg(a+15)=(tga+tg15)/(1-tga.tg15)=2,则tga+tg15=2(1-tga.tg15),得tga=(2-tg15)/(1+tg15}
tg15=tg(30/2)=sin30/(1+cos30)=0.5/(1+0.5√3).把结果代入则可求得tg(a+60)的值.