L1 :( x-3)/2 = (y+1)/4 = (z+3)/-1
L2: (x+1)/-5 = (y-5)/2 = (z+1)/-3

Find a vector equation of a ine that is perpendicular to both L1 and L2 and passes through point P (0,2,1)

Question

L1 :( x-3)/2 = (y+1)/4 = (z+3)/-1 
L2: (x+1)/-5 = (y-5)/2 = (z+1)/-3

Find a vector equation of a ine that is perpendicular to both L1 and L2 and passes through point P (0,2,1)

anonymous · Answer

Apply crossed product for 2 vectors u x v = < 2, 4, -1> x < -5, 2, -3> Then the perpendicular line is: ( 0, 2, 1) + ( u x v ) t

anonymous · Answer

the cross product between the 2 normal vectors? or just any vectors?

anonymous · Answer

cuz when a question asks for "perpendicular" , dont i always cross the normal vectors?

anonymous · Answer

Read my instruction, will you! u x v = < 2, 4, -1> x < -5, 2, -3>

anonymous · Answer

yep i did. nvm, it's my confusion. i thought always need to cross the normal vector
thanks then!

anonymous · Answer

u x v is the vector perpendicular to both u and v vectors by theorem!

anonymous · Answer

yep, i think i get it now thanks

anonymous · Answer

Just my luck :)