We _______ having a big party.( )
A:am
B:are
C:is
函数f(x)=2ax2﹣2bx﹣a+b(a,b∈R,a>0),g(x)=2ax﹣2b
(1)若θ∈0,π2时,求f(sinθ)的最大值;
(2)设a>0时,若对任意θ∈R,都有|f(sinθ)|≤1恒成立,且g(sinθ)的最大值为2,求f(x)的表达式.