Please help with these three question it is Linear algebra 1.

1 2 1 3.Leta= 2 ,b= 4 ,c= 0 1 2 1 (a) Show that b is parallel to a; and c is perpendicular to a. (b) Find P, the projection matrix onto 3, the span of a. (c) Find projs (b) and projs(c). 4. (a) Find the equation of the straight line which best ts the following points (2, 3), (1, 2), (0,2), (1,1), and (2,1). 1 2 1 1 (b) Let A = 1 0 . Find P, the projection matrix on GM). 1 1 1 2 5. The pressure P is a linear function of temperature T. For T = 1, P = 3. For T = 2, P = 4 and for T = 3, P = 4.5. What is the best guess fro P when T = 4'