Consider vectorsv1,v2,v3 inR^4; we are told that (vi dotvj) is the entryaij of matrix A. A =

[3 5 11]

[5 9 20]

[11 20 49].

Find length of (v1 +v2). For this I got 2(sqrt(3)). Can someone check this?

Also, find projV(v3), where V = span(v1,v2). Express your answer as a linear combination ofv1 andv2.