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 $$$\int_{-1}^{2}\left( - t \right)dt$$$
First, calculate the corresponding indefinite integral: $$$\int{\left(- t\right)d t}=- \frac{t^{2}}{2}$$$ (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.
$$$\left(- \frac{t^{2}}{2}\right)|_{\left(t=2\right)}=-2$$$
$$$\left(- \frac{t^{2}}{2}\right)|_{\left(t=-1\right)}=- \frac{1}{2}$$$
$$$\int_{-1}^{2}\left( - t \right)dt=\left(- \frac{t^{2}}{2}\right)|_{\left(t=2\right)}-\left(- \frac{t^{2}}{2}\right)|_{\left(t=-1\right)}=- \frac{3}{2}$$$
Answer: $$$\int_{-1}^{2}\left( - t \right)dt=- \frac{3}{2}=-1.5$$$