Answer
$$ \approx 1.19629$$
Work Step by Step
$$\eqalign{
& \int_{ - 1}^1 {{e^{ - 2{x^2}}}} dx \cr
& {\text{Using a computer algebra system }}\left( {{\text{Wolfram website}}} \right){\text{ we obtain}} \cr
& \int_{ - 1}^1 {{e^{ - 2{x^2}}}} dx \approx 1.19629 \cr} $$
