Calculadora de Integrais Definidas e Impróprias
Calcule integrais definidas e impróprias passo a passo
A calculadora tentará calcular a integral definida (isto é, com limites), inclusive no caso impróprio, com os passos mostrados.
Solution
Your input: calculate $$$\int_{4}^{8}\left( 8 x^{2} + 5 x - 9 \right)dx$$$
First, calculate the corresponding indefinite integral: $$$\int{\left(8 x^{2} + 5 x - 9\right)d x}=\frac{x \left(16 x^{2} + 15 x - 54\right)}{6}$$$ (for steps, see indefinite integral calculator)
According to the Fundamental Theorem of Calculus, $$$\int_a^b F(x) dx=f(b)-f(a)$$$, so just evaluate the integral at the endpoints, and that's the answer.
$$$\left(\frac{x \left(16 x^{2} + 15 x - 54\right)}{6}\right)|_{\left(x=8\right)}=\frac{4360}{3}$$$
$$$\left(\frac{x \left(16 x^{2} + 15 x - 54\right)}{6}\right)|_{\left(x=4\right)}=\frac{524}{3}$$$
$$$\int_{4}^{8}\left( 8 x^{2} + 5 x - 9 \right)dx=\left(\frac{x \left(16 x^{2} + 15 x - 54\right)}{6}\right)|_{\left(x=8\right)}-\left(\frac{x \left(16 x^{2} + 15 x - 54\right)}{6}\right)|_{\left(x=4\right)}=\frac{3836}{3}$$$
Answer: $$$\int_{4}^{8}\left( 8 x^{2} + 5 x - 9 \right)dx=\frac{3836}{3}\approx 1278.66666666667$$$