Basis projection
= Basis projection
{title2=$P_n$}
The nth basis projection associated with a <Schauder basis> is
$$
P_n\left(\sum_{k=1}^\infty a_ke_k\right)=\sum_{k=1}^na_ke_k.
$$
= Basis projection
{title2=$P_n$}
The nth basis projection associated with a <Schauder basis> is
$$
P_n\left(\sum_{k=1}^\infty a_ke_k\right)=\sum_{k=1}^na_ke_k.
$$