一、选择题 (1sim 6 小题,每题3分,共18分)-|||-1.设函数 f(x)= ^a-1),1lt xlt e dfrac (1)(x{ln )^(a^{a^-1x),xgeqslant e,f(x)dx=0, 则至少在[a,b]内至少存在一点ξ,使 (xi )=0-|||-6.设f(x)是连续函数,F(x)为f(x )的任一原函数,则 ()-|||-(A)当f(x)为奇函数时,F(x)必为偶函数-|||-(B)当f(x)为偶函数时,F(x)必为奇函数-|||-(C)当f(x)为周期函数时,F(x)必为周期函数-|||-(D)当f(x)为单增函数时,F(x)必为单增函数