3. Which two of the following lines are the same? Explain. a. [x,y,z]=[1,2,3]+s[3,1,2] b. [x,y,z]=[2,3,1]+t[3,1,2] c. [x,y,z]=[7,0,6]+p[3,-1,-2] 4. The points A (1 , 2 , 3) , B (-1 , 3 , 2) , and C (3 , -2 , -1) are given. a. Determine a vector equation of the line that passes through A and that is parallel to the segment BC. b. Determine the parametric equations of the line that passes through B and that is parallel to the segment AC. 0. Determine the symmetric equations of the line that passes through C and that is parallel to the segment AB. . Two lines with the following symmetric equations are given. a) Prove that L1 and L; are skew lines. b) Find the equations of two parallel planes containing L1 and L2. 12. The equations of three planes are given. 7: x+ 2y+ 3z =-4 2 : x-y - 3z =8 73 : 2x+ y+ 6z =-14 a) Show that the three planes intersect at a single point. b) Find the coordinates of the point of intersection. 13. Show that the following planes form a triangular prism. 7, : 3x + 2y + z =0 1, : x+2y + 3z =4 J, : x+ V+z = 16