1. The problem statement, all variables and given/known data My problem is one pertaining to my Vector Calculus course. The assignment is asking us to "Find equations for the planes tangent to z = x2 + 6x + y3 that are parallel to the plane 4x − 12y + z = 7." The problem I'm having with the problem is the plural aspect. It states to find "Equation-S". Variables are x, y, and z 2. Relevant equations To reiterate: z = x2 + 6x + y3 4x − 12y + z = 7 General form of the graph of a tangent plane z = f(a,b) + fx(a,b)(x - a) + fy(a,b)(y - b) 3. The attempt at a solution I understand that in order to find a tangent plane to a particular point on the graph of some function one must compute the partial derivatives of the original function and then compute the remaining portion from the point that is given. zx = 2x - 6 zy = 3y2 What is confusing me is the part about the plural. Is the plural part hanging me up and getting in the way, or do I use the normal vector to attempt to find a point on the original plane? In addendum: I would like to apologize that my equations aren't in the proper TeX format. I'm only just getting the hang of writing TeX scripts.