设三条直线的方程分别为L1:(x+3)/-2=(y+4)/-5=z/3,L2:{x=3t,{y=-1+3t,{z=2+7t;L3:{x+2y-z+1=0,{2x+y-z=0,则必有()
A.L1∥L3 B.L1∥L2 C.L2⊥L3 D.L1⊥L2正确答案D
设三条直线的方程分别为L1:(x+3)/-2=(y+4)/-5=z/3,L2:{x=3t,{y=-1+3t,{z=2+7t;L3:{x+2y-z+1=0,{2x+y-z=0,则必有()
A.L1∥L3 B.L1∥L2 C.L2⊥L3 D.L1⊥L2正确答案D