当 x>=1, f(x)= ;当x<1 , f(x)= x2+3
A.Select Case xCase Is<1f= x^2+3Case elsef=sqr(x+1 )End Select
B.Select Case xCase x>=1f=sqr(x+1 )Case x<1f= x^2+3End Select
C.Select Case xCase Is>=1f=sqr(x+1 )Case Is<1f= x^2+3End Select
D.IF x>=1 thenf=sqr(x+1 ) else f=x^2+3
A.(x)=x^2和f(x)=(x+1)^2
B.(x)=(根号x)^2 / x 和f(x)=x/ (根号x)^2
C.(x)=log以a为底x^2的对数和f(x)=2log以a为底x的对数
D.(x)=x-1和f(x)=根号(x-1)^2
已知函数f(x)=1og3(x+1)+log3(5-x),则f(x)的()
A.最大值为3
B.最大值为9
C.最大值为2
D.最小值为2