$X,Y$ are norm linear space and $T_n$ be a sequence of bounded linear operators from $X\to Y$ consider the two statements below
$P:\{\|T_n(x)\|\}$ is bounded for ever $n$
$Q:\{\|T_n\|\}$ is bounded for every $n$
which of the following statements is correct?
if $P\Rightarrow Q$ Then both are banach space
if $P\Rightarrow Q$ Then one of them is banach space
If $X$ is a banach space then $P\Rightarrow Q$
if $Y$ is a banach space then $P\Rightarrow Q$
I am completely lost. could anyone help me to solve?or neccessary information which will help me to solve?
For $1)$ and $2)$ take non-complete normed spaces, take any non-zero linear bounded operator $T:X\to Y$. To get a counterexample set $T_n=T$ for all $n\in\mathbb{N}$.
Statement $3)$ is correct by uniform boundedness principle.
For $4)$ see this counterexample.