I'm stuck on this....

Problem:

Show that (tn) is a nonincreasing sequence. That is, use induction to prove that where

I have the base case so, . Then assume .

But I'm stuck at this part. I don't know how to arrive at . I tried messing with the inequalities and stuff, but I'm still not sure.

Edit: The only thing I could really come up with was .....

then use the fact and so