integral (limits: a = -1 and b = 1) or $\displaystyle 5e^-2x^2$ (the Latex max confuse: 5e^-2x^2) using 4 strips.

Length = 2 and width = 0.6

$\displaystyle E = 0.677 + 0.677 = 1.354$

$\displaystyle M = 0.169 + 0.169 = 0.338$

$\displaystyle f(x) dx = 1/2 w (E + 2M)$

= 0.25 (1.354 + 2 * 0.338)

= 0.5075

But the answer is actually 5.87...