## Elementary Geometry for College Students (7th Edition)

(a) A direction vector is $(4,2,3)$ (b) $(x,y,z) = (-1,2,4)+n(4,2,3)$
(a) We can find a direction vector: $P_2-P_1 = (3,4,7) - (-1,2,4) = (4,2,3)$ A direction vector is $(4,2,3)$ (b) We can find an equation for this line: $(x,y,z) = (-1,2,4)+n(4,2,3)$, where $n$ is a real number