# Homework Help: Inner product for work

1. Sep 2, 2014

### princejan7

1. The problem statement, all variables and given/known data

http://postimg.org/image/lgphyvggz/

2. Relevant equations

3. The attempt at a solution

can someone explain where that transpose came from in (3.3)?

2. Sep 3, 2014

### HallsofIvy

In any inner product space the "transpose" (more generally, "adjoint") of a linear operator is defined by $<u, Av>= <A^Tu, v>$.

3.3 is just saying that $<Au, Av>= <A^T(Au), v>$