hi :)

I know the power series representation of sin x is Sum [ (-1)^n*(x)^(2n+1)/(2n+1)!] but what about(sinx)^2?

another quick question :

give an example of set A that has no supremum and why does it not violate the Completeness Axiom.

is {tanx : 0 < x < pi/2} correct?