设函数f(x)在[a，b]上连续，在(a，b)可导，f'(x)>0，f(a)／f(b)<0，则f(x)在(a，b)内零点的个数为【】

A 等价无穷小 B 2阶无穷小 C 3阶无穷小 D 4阶无穷小

A -e² B -e C e D e²

A 2sin2x B -2sin2x C sin2x D -sin2x

A 0 B 2 C x² D x²+C

A -arctanx+C B <img src="https://www.beizhujiaoyu.com/uploads/202208/162089185577731.png" width="100" height="34" />  C arctanx+C D <img src="https://www.beizhujiaoyu.com/uploads/202208/162089186251431.png" width="82" height="33" />

A I1>I2>I3 B I2>I3>I1 C I3>I2>I1 D I1>I3>I2

A 0 B <img src="https://www.beizhujiaoyu.com/uploads/202208/162089187764381.png" width="20" height="52" /> C 1 D 2

A {1，一3，4) B {1，2，4} C {1，2，-3) D {2，-3，4}

A 1 B 2 C 3 D 4