Question: part a makes sense but can you please answer parts...

Part A makes sense, but can you PLEASE answer parts b. and c.???

The question uses the tangent plane formula.

A)Find the equation of the tangent plane to the cone z=√(x^2+y^2) at the point Q:(a, b, c) on the cone. (As an equation containing x,y,z as variables and a,b,c as constants.

B)Explain why the ray from the origin passing through Q is given by all points of the form x= ta, y= tb, z=tc with t from 0 to infinity.

C)Show that the ray from part B lies both on the cone and the tangent plane at Q.