\(n=3\):
\(n=4\):
Für \(\displaystyle n = 2: \int_a^b f(x)\,dx \approx \frac{b-a}{2} \big(f(x_1) + f(x_2)\big)\)mit\[ x_1 = \frac{a+b}{2} - \frac{b-a}{2} \sqrt{ \frac{1}{3} };\quad x_2 = \frac{a+b}{2} + \frac{b-a}{2} \sqrt{ \frac{1}{3} } \]Für \(\displaystyle n = 3: \int_a^b f(x)\,dx \approx \frac{b-a}{18} \big(5\, f(x_1) + 8\, f(x_2) + 5\, f(x_3))\big)\)mit \[ x_1 = \frac{a+b}{2} - \frac{b-a}{2} \sqrt{ \frac{3}{5} };\quad x_2 = \frac{a+b}{2}; \quad x_3 = \frac{a+b}{2} + \frac{b-a}{2} \sqrt{ \frac{3}{5} } \]
Für \(n=2\) lautet die Gauß-Formel: \[ \int_a^b f(x)\,dx \approx \frac{b-a}{2} \big(f(x_1) + f(x_2)\big)\]mit\[ x_1 = \frac{a+b}{2} - \frac{b-a}{2} \sqrt{ \frac{1}{3} };\quad x_2 = \frac{a+b}{2} + \frac{b-a}{2} \sqrt{ \frac{1}{3} } \]