This isn't my hw, but I want to know how to do these questions
1. Consider the point P=(1,3,0).
(a) Find the equation for the plane containing P and lying perpendicular
to the vector <1,2,1>
(b) Find the vector equation for the line passing through P that is orthog-
onal to the plane found in part (a).
I found (a) to be (x-1)+2(y-3)+z=0. I don't know what to do afterwards
2. Consider the vector-valued function r(t) = (e^(t-1),cos(((pi*t)/2))
(a) Find r'(1).
(b) Find a vector orthogonal to the curve r(t) at the point (1,0).
I know how to do a, not (b). Do you just find the normal vector at point (1,0)?