So I know the formulas for the errors but I don't know what I'm supposed to plug into the formulas... It's very hard to find some examples rather than raw definitions so I'm kind of stuck. Should I solve the initial integral as if it were a regular integral to move on or I'm to plug something into the formula right from the beginning?For an integral of form $\displaystyle \int_{-2}^2 x^2e^xdx$, calculate the Newton-Cotes quadrature and estimate the error for:

- $\displaystyle n=1$ (Trapezoid rule)

- $\displaystyle n=2$ (Simpson's rule)

- $\displaystyle n=3$ (3/8 rule)