g(x)=e^x(x^2-3)求单调区间

问题描述:

g(x)=e^x(x^2-3)求单调区间

g(x)=(e^x)(x²-3)求单调区间g'(x)=(e^x)(x²-3)+2x(e^x)=(e^x)(x²+2x-3)=(e^x)(x+3)(x-1)由于e^x>0对任何x都成立,故g'(x)的符号取决于(x+3)(x-1)的符号.用根轴法很快求得:当x≦-3或x≧1时g'(x)≧0,因...