Answer
$2/(1-2^{\wedge}(-4*x))$
Work Step by Step
$2/(1-2^{\wedge}(-4*x))$
The denominator must be enclosed in parentheses,
and the exponent must be enclosed in parentheses,
otherwise,
Without (denominator) you woud generate $\displaystyle \frac{2}{1}-2^{-4x}$.
With (denominator), but without (exponent),
you woud generate $\displaystyle \frac{2}{1-2^{-4}\cdot x}$
