Suppose $X$ is a separable infinite dimensional Banach space, $E$ a finite dimensional subspace which is $c$-complemented in $X$. Is the following true?
For any $\epsilon>0$, one can find $x\notin E$ such that $span\{E,x\}$ is $c+\epsilon$ complemented.
This is obviously true in Hilbert spaces, but not sure in general Banach spaces. Would reflexivity make a difference?