已知sin方2a+sin2acosa-cos2a=1,a=(0.π⼀2),求sinatana

2024-12-27 00:37:38
推荐回答(1个)
回答1:

sin方2a+sin2acosa-cos2a=1
sin方2a+sin2acosa-2(cosa)^2+1=1
4(sina)^2(cosa)^2+2sina(cosa)^2-2(cosa)^2=0
2(sina)^2+sina-1=0
(2sina-1)(sina+1)=0
sina=1/2
cosa=√3/2
tana=√3/3

所以
sinatana=√3/6