mm-crj

It seems its based on the reflexivity of the subspace

I remember studying the best approximation is unique in a Hilbert space .. but we don't need uniqueness

Its related to the best approximation to a closed subspace no?

I mean for other f

I am thinking .. that to prove the norm by the bi-directional inequalities one needs to guess the value first .. is there a way to do this?

Si, I am looking at it.. :)

$\left\lVert h\right\rVert_{\infty}$

So we are trying to find $left\lVert h\right\rVert$_{\infty} where $h \in C[0,\pi]$ and $\int_{0}^{\pi}h(t)dt=2$.. right?

@MartinSleziak Btw why do you need the integral to be 1. The kernel of the map is with integral zero .. no?