Let $$h(x)=\frac{\phi(x)}{\Phi(x)}$$
where $\phi$ and $\Phi$ are PDF and CDF of standard normal distribution.
Can we tell that $$h'(x)\geq -1$$ for all $x\in (-\infty,+\infty)$ and $$x+h(x)\geq 0$$ for all $x\in (-\infty,+\infty)$ ?
Let $$h(x)=\frac{\phi(x)}{\Phi(x)}$$
where $\phi$ and $\Phi$ are PDF and CDF of standard normal distribution.
Can we tell that $$h'(x)\geq -1$$ for all $x\in (-\infty,+\infty)$ and $$x+h(x)\geq 0$$ for all $x\in (-\infty,+\infty)$ ?
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