# Thread: Orthonormal basis of inner product

1. ## Orthonormal basis of inner product

Assume e1,e2 is an orthonormal basis of an inner product vector space V and let v=5e1-e2
Find a) ||v+3e2||
and
B) 7<v,e1>-10<v,e2>

This is what o have for a) ||5e1+2e2||=||(5,2)||=sq.root of 29. I'm not sure if I computed this right any help??

And for b) I replaced v the same way but undone know the formula I should be using because my textbook sucks.
Thank u!!!!

2. Part (a) is correct.

$v=\begin{bmatrix}
5\\
-1
\end{bmatrix}$

$=x^Ty$