[Sec. 10.5] Let

L_(1)

and

L_(2)

be the lines whose vector equations are\

L_(1):r_(1)(t)=(:1,2,4:)+t(:2,-1,-2:)\ L_(2):r_(2)(t)=(:9,5,-4:)+t(:1,3,-1:)

\ (a) Show that

L_(1)

and

L_(2)

intersect at the point

(7,-1,-2)

. I\ (b) Find, to the nearest degree, the acute angle between

L_(1)

and

L_(2)

at their intersection.\ (c) Find the vector equation of the line that is perpendicular to

L_(1)

and

L_(2)

and passes through their point of intersection.

8. [Sec. 10.5] Let L1 and L2 be the lines whose vector equations are L1:r1(t)=1,2,4+t2,1,2L2:r2(t)=9,5,4+t1,3,1 (a) Show that L1 and L2 intersect at the point (7,1,2). I (b) Find, to the nearest degree, the acute angle between L1 and L2 at their intersection. (c) Find the vector equation of the line that is perpendicular to L1 and L2 and passes through their point of inter