记cos(-80°)=k,那么tan100°等于

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记cos(-80°)=k,那么tan100°等于
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记cos(-80°)=k,那么tan100°等于
记cos(-80°)=k,那么tan100°等于

记cos(-80°)=k,那么tan100°等于
cos(-80°)=k
即cos(80°)=k
即cos(100°)=-k
sin(100°)=根号(1-k^2)
故tan(100°)=根号(1-k^2)/(-k)

cos(-80°)=cos80°=k
∵80°为锐角,∴sin80°>0
又cos^2 80°+sin^2 80°=1
所以sin80°=根号1-k^2
tan100°=-tan80°=-(根号1-k^2/k)
但愿可以帮到你

tan100=tan(60+40),cos(-80)=2cos(40)*cos(40)-1,cos40cos(40)=(1+k)/2,sin(40)*sin(40)=(1-k)/2; tan(40)*tan(40)=(1-k)/(1+k),

tan100°=tan(-80°)=sin(-80°)/cos(-80°)=﹣(1-k²)½/k