5.已知f(x-1)=x-x+1,则函数f(x)在[-1,1]上的最小值为3A1题B.1序C32D.26.已知函数f(x)=(3)x+,函数g(x)=(a+2x-x2在[,+∞)上单调递减,则f(a)的取值范围是A.[-q,+∞)B.[1,+∞)C.(-∞,-2]D.[3,+∞)已知函数f(x)的定义域为R,且y=f(x+1是偶函数.当x<1时,f(x)=2x+3,则当x>1时,f(x)x-,2x+1Ax+1-x2x+1x鸟瞰图100%x-1D2x-7x-1