Question

Find an equation of the plane through the three points (1,0,1), (0,2,0), (0,0,3).

Answer 1

I can go into details but here is the gist:

You have 3 points: A, B and C

Make 2 vectors out of those 3 points. AB and AC. The two vectors, which both have tails at A, form a plane.

Take the Cross Product ABxAC, which gives a vector perpendicular to both. This is the Normal Vector of the plane.

Plane Equation:

(r−r0) * (n) = 0

The star, right now, for the purpose of this, designates dot product

Answer 2

have you learn about vector?
or what topics are you learning?