定積分・広義積分計算機
定積分と広義積分を手順を追って計算する
この計算機は、定積分(すなわち上下限のある積分)を、広義積分も含めて、解法手順を示しながら計算を試みます。
Solution
Your input: calculate $$$\int_{\frac{\pi}{4}}^{\pi}\left( \sin{\left(x \right)} \right)dx$$$
First, calculate the corresponding indefinite integral: $$$\int{\sin{\left(x \right)} d x}=- \cos{\left(x \right)}$$$ (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.
$$$\left(- \cos{\left(x \right)}\right)|_{\left(x=\pi\right)}=1$$$
$$$\left(- \cos{\left(x \right)}\right)|_{\left(x=\frac{\pi}{4}\right)}=- \frac{\sqrt{2}}{2}$$$
$$$\int_{\frac{\pi}{4}}^{\pi}\left( \sin{\left(x \right)} \right)dx=\left(- \cos{\left(x \right)}\right)|_{\left(x=\pi\right)}-\left(- \cos{\left(x \right)}\right)|_{\left(x=\frac{\pi}{4}\right)}=\frac{\sqrt{2}}{2} + 1$$$
Answer: $$$\int_{\frac{\pi}{4}}^{\pi}\left( \sin{\left(x \right)} \right)dx=\frac{\sqrt{2}}{2} + 1\approx 1.70710678118655$$$