E^(-x) less than 1-(x/2) for 0 less than x less than or equal to 1.5936
From specialfunctionswiki
Theorem
The following formula holds for $0 < x \leq 1.5936$: $$e^{-x} < 1 - \dfrac{x}{2},$$ where $e^{-x}$ denotes the exponential.
Proof
References
- 1964: Milton Abramowitz and Irene A. Stegun: Handbook of mathematical functions ... (previous) ... (next): 4.2.37