f(x)=-f(x+3/2),得到
f(x+3/2)=-f(x)
f(x+3)=f(x+3/2+3/2)=-f(x+3/2)=f(x)
所以f(x)的周期为3
而2012=670*3+2
f(2012)=f(670*3+2)=f(2)=1