Q1241 Show that Simpson's Elementary Rule
$$ \int^b_a f (x) dx \approx \left(\frac{b-a}{6}\right)\left( f(a) + 4f\left(\frac{a+b}{2}\right) + f(b)\right)$$
is an exact equality for the quadratic function
$$f(x) = Ax^2 + Bx + C.$$
Q1241 Show that Simpson's Elementary Rule
$$ \int^b_a f (x) dx \approx \left(\frac{b-a}{6}\right)\left( f(a) + 4f\left(\frac{a+b}{2}\right) + f(b)\right)$$
is an exact equality for the quadratic function
$$f(x) = Ax^2 + Bx + C.$$