A+B=90°,则tanA/2+tanB/2+tanA/2tanB/2=
问题描述:
A+B=90°,则tanA/2+tanB/2+tanA/2tanB/2=
答
A+B=90°,A/2+B/2=45º
tan(A/2+B/2)=(tanA/2+tanB/2)/(1-tanA/2tanB/2)=1
tanA/2+tanB/2=1-tanA/2tanB/2
tanA/2+tanB/2+tanA/2tanB/2=1-tanA/2tanB/2+tanA/2tanB/2=1