Kalkylator för bestämda och oegentliga integraler
Beräkna bestämda och oegentliga integraler steg för steg
Kalkylatorn försöker beräkna bestämda integraler (dvs. med integrationsgränser), inklusive oegentliga, och visar stegen.
Solution
Your input: calculate $$$\int_{\frac{1}{4}}^{\frac{1}{3}}\left( 3 - 6 x^{2} \right)dx$$$
First, calculate the corresponding indefinite integral: $$$\int{\left(3 - 6 x^{2}\right)d x}=x \left(3 - 2 x^{2}\right)$$$ (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.
$$$\left(x \left(3 - 2 x^{2}\right)\right)|_{\left(x=\frac{1}{3}\right)}=\frac{25}{27}$$$
$$$\left(x \left(3 - 2 x^{2}\right)\right)|_{\left(x=\frac{1}{4}\right)}=\frac{23}{32}$$$
$$$\int_{\frac{1}{4}}^{\frac{1}{3}}\left( 3 - 6 x^{2} \right)dx=\left(x \left(3 - 2 x^{2}\right)\right)|_{\left(x=\frac{1}{3}\right)}-\left(x \left(3 - 2 x^{2}\right)\right)|_{\left(x=\frac{1}{4}\right)}=\frac{179}{864}$$$
Answer: $$$\int_{\frac{1}{4}}^{\frac{1}{3}}\left( 3 - 6 x^{2} \right)dx=\frac{179}{864}\approx 0.207175925925926$$$