若∠A为锐角,且tan2A+2tanA-3=0,则∠A=_度.
问题描述:
若∠A为锐角,且tan2A+2tanA-3=0,则∠A=______度.
答
tan2A+2tanA-3=0,
(tanA-1)(tanA+3)=0,
解得tanA=-3(舍去),tanA=1.
∴∠A=45°.