1. The problem statement, all variables and given/known data Find an equation of the plane that passes through the points (4,2,1) and (-2, 9, 6), and is parallel to the z axis. 2. Relevant equations a(X-Xo) + b(Y-Yo) + c(Z-Zo) = 0 3. The attempt at a solution Okay so for this one, I first tried to make a vector out of the two given points. If P(4,2,1) and Q(-2,9,6), then PQ = <-6,7,5>. Next I fumbled around a bit trying to figure out how to either a) find another vector to form a cross product with, or b) somehow figure out what the <a,b,c> numbers should look like in order to be parallel to z axis. When I tried approach a) I came up with another point on the z axis, (0,0,1), used it as a vector of its own, crossed it with PQ, picked up the resultant, and plugged in the direction numbers to the plane equation. For part b) I tried making a vector out of (0,0,1) and P, crossing it with PQ and using the resultant direction numbers. However, both approaches seem to be rather wrong.