Question

已知sin a=负的二分之根号三,并且是第四象限,求cos a,tan a,sec2 a

Answer 1

cosa=√[1-(sina)^2]=√[1-(-√3/2)^2]=1/2

tana=sina/cosa=-√3/2/(1/2)=-√3

seca=1/cosa=1/(1/2)=2

(seca)^2=4