

For the first, use the ]Cauchy-Schwarz inequality,, and its consequence,
.
The second looks straight forward. First, since T is 1-1 and onto, it has and inverse, a function, fro Y to X such that
for all x in X and
for all y in Y. Now, suppose u and v are in X and let p= T(u), q= T(v). What can you say about
?