1
射线l:y=2√2x (x>=0)
tana=2√2 cosa>0,sina>0
(cosa)^2=1/(1+(tana)^2)=1/9
cosa=1/3 sina=2√2/3
sin(a+30)=sinacos30+cosa*sin30=(2√2/3)(√3/2)+(1/3)*(1/2)=(1+2√6)/6
2
p(x0,0),q(x1,2√2x1)
pq^2=(x0-x1)^2+(2√2x1)^2=x0^2+9x1^2-2x0x1=16
Spoq=x0 *(2√2x1)/2=x0*(√2x1)