点p（-√3,m),则有：sina=m/√(3+m^2)由sina=√2m/4, 得方程 m/√(3+m^2)=√2m/4, 解得：m=0 or m=√5, or -√5m=0, sina=-1, cosa=0, tana无穷大m=√5, sina=√10 /4, cosa=-√6 /4, tana=-√(5/3)m=-√5, sina=-√10/4, cosa=-√6/4, tana=√(5/3)
