x+x / √(x^2-1)=2√2
设secy=x x^2-1=tan²y
则secy+secy*cosy/siny=2√2
1/cosy+1/siny=2√2
siny+cosy=2√2sinycosy
(√2/2)siny+(√2/2)cosy=sin2y
sin(y+π/4)=sin2y
y+π/4=2y y=π/4
所以x=sec(π/4)=√2
x+x / √(x^2-1)=2√2
设secy=x x^2-1=tan²y
则secy+secy*cosy/siny=2√2
1/cosy+1/siny=2√2
siny+cosy=2√2sinycosy
(√2/2)siny+(√2/2)cosy=sin2y
sin(y+π/4)=sin2y
y+π/4=2y y=π/4
所以x=sec(π/4)=√2