【用戶】我
【年級】大一下
【評論內容】令L之參數式為x=2t+1,y=2t-1,z=t+2,t為任意實數將其代入S eq.得(2t)^2+(2t-5)^2+(t+1)^2=17展開化簡t^2-2t+1=0(t-1)^2=0t=1故L與S交於一點,為(3,1,3)答案:(A)