Para hallar los extremos hay que resolver la ecuación
$$\frac{d}{d x} f{\left(x \right)} = 0$$
(la derivada es igual a cero),
y las raíces de esta ecuación serán los extremos de esta función:
$$\frac{d}{d x} f{\left(x \right)} = $$
primera derivada$$3 x^{2} \left(\left(x^{2} + x\right) + 1\right) + \left(2 x + 1\right) \left(x^{3} - 2\right) = 0$$
Resolvermos esta ecuaciónRaíces de esta ecuación
$$x_{1} = - \frac{1}{5} + \frac{\sqrt{- \frac{7}{50 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}}} - \frac{6}{25} + 2 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}}}}{2} + \frac{\sqrt{- 2 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}} - \frac{12}{25} + \frac{7}{50 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}}} + \frac{244}{125 \sqrt{- \frac{7}{50 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}}} - \frac{6}{25} + 2 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}}}}}}{2}$$
$$x_{2} = - \frac{\sqrt{- 2 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}} - \frac{12}{25} + \frac{7}{50 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}}} + \frac{244}{125 \sqrt{- \frac{7}{50 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}}} - \frac{6}{25} + 2 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}}}}}}{2} - \frac{1}{5} + \frac{\sqrt{- \frac{7}{50 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}}} - \frac{6}{25} + 2 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}}}}{2}$$
Signos de extremos en los puntos:
/ 3\ / 2 \
___________________________________________________________________________________________________________________________________________ | / ___________________________________________________________________________________________________________________________________________\ | | / ___________________________________________________________________________________________________________________________________________\ ___________________________________________________________________________________________________________________________________________|
/ _________________ | | / _________________ | | | | / _________________ | / _________________ |
/ / ______ | | / / ______ | | | | / / ______ | / / ______ |
/ 12 / 73 \/ 1418 7 244 | | / 12 / 73 \/ 1418 7 244 | | | | / 12 / 73 \/ 1418 7 244 | / 12 / 73 \/ 1418 7 244 |
/ - -- - 2*3 / ---- + -------- + ------------------------- + --------------------------------------------------------------------------- | | / - -- - 2*3 / ---- + -------- + ------------------------- + --------------------------------------------------------------------------- | | | | / - -- - 2*3 / ---- + -------- + ------------------------- + --------------------------------------------------------------------------- | / - -- - 2*3 / ---- + -------- + ------------------------- + --------------------------------------------------------------------------- |
_____________________________________________________________ / 25 \/ 1000 500 _________________ _____________________________________________________________ | | _____________________________________________________________ / 25 \/ 1000 500 _________________ _____________________________________________________________ | | | | _____________________________________________________________ / 25 \/ 1000 500 _________________ _____________________________________________________________ | _____________________________________________________________ / 25 \/ 1000 500 _________________ _____________________________________________________________ |
/ _________________ / / ______ / _________________ | | / _________________ / / ______ / _________________ | | | | / _________________ / / ______ / _________________ | / _________________ / / ______ / _________________ |
/ / ______ / / 73 \/ 1418 / / ______ | | / / ______ / / 73 \/ 1418 / / ______ | | | | / / ______ / / 73 \/ 1418 / / ______ | / / ______ / / 73 \/ 1418 / / ______ |
/ 6 / 73 \/ 1418 7 / 50*3 / ---- + -------- / 6 / 73 \/ 1418 7 | | / 6 / 73 \/ 1418 7 / 50*3 / ---- + -------- / 6 / 73 \/ 1418 7 | | | | / 6 / 73 \/ 1418 7 / 50*3 / ---- + -------- / 6 / 73 \/ 1418 7 | / 6 / 73 \/ 1418 7 / 50*3 / ---- + -------- / 6 / 73 \/ 1418 7 |
/ - -- + 2*3 / ---- + -------- - ------------------------- / \/ 1000 500 125* / - -- + 2*3 / ---- + -------- - ------------------------- | | / - -- + 2*3 / ---- + -------- - ------------------------- / \/ 1000 500 125* / - -- + 2*3 / ---- + -------- - ------------------------- | | | | / - -- + 2*3 / ---- + -------- - ------------------------- / \/ 1000 500 125* / - -- + 2*3 / ---- + -------- - ------------------------- | / - -- + 2*3 / ---- + -------- - ------------------------- / \/ 1000 500 125* / - -- + 2*3 / ---- + -------- - ------------------------- |
/ 25 \/ 1000 500 _________________ / / 25 \/ 1000 500 _________________ | | / 25 \/ 1000 500 _________________ / / 25 \/ 1000 500 _________________ | | | | / 25 \/ 1000 500 _________________ / / 25 \/ 1000 500 _________________ | / 25 \/ 1000 500 _________________ / / 25 \/ 1000 500 _________________ |
/ / ______ / / / ______ | | / / ______ / / / ______ | | | | / / ______ / / / ______ | / / ______ / / / ______ |
/ / 73 \/ 1418 / / / 73 \/ 1418 | | / / 73 \/ 1418 / / / 73 \/ 1418 | | | | / / 73 \/ 1418 / / / 73 \/ 1418 | / / 73 \/ 1418 / / / 73 \/ 1418 |
/ 50*3 / ---- + -------- / / 50*3 / ---- + -------- | | / 50*3 / ---- + -------- / / 50*3 / ---- + -------- | | | | / 50*3 / ---- + -------- / / 50*3 / ---- + -------- | / 50*3 / ---- + -------- / / 50*3 / ---- + -------- |
1 \/ \/ 1000 500 \/ \/ \/ 1000 500 | | 1 \/ \/ 1000 500 \/ \/ \/ 1000 500 | | |4 | 1 \/ \/ 1000 500 \/ \/ \/ 1000 500 | \/ \/ 1000 500 \/ \/ \/ 1000 500 |
(- - + ----------------------------------------------------------------------- + ----------------------------------------------------------------------------------------------------------------------------------------------------------, |-2 + |- - + ----------------------------------------------------------------------- + ----------------------------------------------------------------------------------------------------------------------------------------------------------| |*|- + |- - + ----------------------------------------------------------------------- + ----------------------------------------------------------------------------------------------------------------------------------------------------------| + ----------------------------------------------------------------------- + ----------------------------------------------------------------------------------------------------------------------------------------------------------|)
5 2 2 \ \ 5 2 2 / / \5 \ 5 2 2 / 2 2 /
/ 3\ / 2 \
___________________________________________________________________________________________________________________________________________ | / ___________________________________________________________________________________________________________________________________________\ | | / ___________________________________________________________________________________________________________________________________________\ ___________________________________________________________________________________________________________________________________________|
/ _________________ | | / _________________ | | | | / _________________ | / _________________ |
/ / ______ | | / / ______ | | | | / / ______ | / / ______ |
/ 12 / 73 \/ 1418 7 244 | | / 12 / 73 \/ 1418 7 244 | | | | / 12 / 73 \/ 1418 7 244 | / 12 / 73 \/ 1418 7 244 |
/ - -- - 2*3 / ---- + -------- + ------------------------- + --------------------------------------------------------------------------- | | / - -- - 2*3 / ---- + -------- + ------------------------- + --------------------------------------------------------------------------- | | | | / - -- - 2*3 / ---- + -------- + ------------------------- + --------------------------------------------------------------------------- | / - -- - 2*3 / ---- + -------- + ------------------------- + --------------------------------------------------------------------------- |
_____________________________________________________________ / 25 \/ 1000 500 _________________ _____________________________________________________________ | | _____________________________________________________________ / 25 \/ 1000 500 _________________ _____________________________________________________________ | | | | _____________________________________________________________ / 25 \/ 1000 500 _________________ _____________________________________________________________ | _____________________________________________________________ / 25 \/ 1000 500 _________________ _____________________________________________________________ |
/ _________________ / / ______ / _________________ | | / _________________ / / ______ / _________________ | | | | / _________________ / / ______ / _________________ | / _________________ / / ______ / _________________ |
/ / ______ / / 73 \/ 1418 / / ______ | | / / ______ / / 73 \/ 1418 / / ______ | | | | / / ______ / / 73 \/ 1418 / / ______ | / / ______ / / 73 \/ 1418 / / ______ |
/ 6 / 73 \/ 1418 7 / 50*3 / ---- + -------- / 6 / 73 \/ 1418 7 | | / 6 / 73 \/ 1418 7 / 50*3 / ---- + -------- / 6 / 73 \/ 1418 7 | | | | / 6 / 73 \/ 1418 7 / 50*3 / ---- + -------- / 6 / 73 \/ 1418 7 | / 6 / 73 \/ 1418 7 / 50*3 / ---- + -------- / 6 / 73 \/ 1418 7 |
/ - -- + 2*3 / ---- + -------- - ------------------------- / \/ 1000 500 125* / - -- + 2*3 / ---- + -------- - ------------------------- | | / - -- + 2*3 / ---- + -------- - ------------------------- / \/ 1000 500 125* / - -- + 2*3 / ---- + -------- - ------------------------- | | | | / - -- + 2*3 / ---- + -------- - ------------------------- / \/ 1000 500 125* / - -- + 2*3 / ---- + -------- - ------------------------- | / - -- + 2*3 / ---- + -------- - ------------------------- / \/ 1000 500 125* / - -- + 2*3 / ---- + -------- - ------------------------- |
/ 25 \/ 1000 500 _________________ / / 25 \/ 1000 500 _________________ | | / 25 \/ 1000 500 _________________ / / 25 \/ 1000 500 _________________ | | | | / 25 \/ 1000 500 _________________ / / 25 \/ 1000 500 _________________ | / 25 \/ 1000 500 _________________ / / 25 \/ 1000 500 _________________ |
/ / ______ / / / ______ | | / / ______ / / / ______ | | | | / / ______ / / / ______ | / / ______ / / / ______ |
/ / 73 \/ 1418 / / / 73 \/ 1418 | | / / 73 \/ 1418 / / / 73 \/ 1418 | | | | / / 73 \/ 1418 / / / 73 \/ 1418 | / / 73 \/ 1418 / / / 73 \/ 1418 |
/ 50*3 / ---- + -------- / / 50*3 / ---- + -------- | | / 50*3 / ---- + -------- / / 50*3 / ---- + -------- | | | | / 50*3 / ---- + -------- / / 50*3 / ---- + -------- | / 50*3 / ---- + -------- / / 50*3 / ---- + -------- |
1 \/ \/ 1000 500 \/ \/ \/ 1000 500 | | 1 \/ \/ 1000 500 \/ \/ \/ 1000 500 | | |4 | 1 \/ \/ 1000 500 \/ \/ \/ 1000 500 | \/ \/ 1000 500 \/ \/ \/ 1000 500 |
(- - + ----------------------------------------------------------------------- - ----------------------------------------------------------------------------------------------------------------------------------------------------------, |-2 + |- - + ----------------------------------------------------------------------- - ----------------------------------------------------------------------------------------------------------------------------------------------------------| |*|- + |- - + ----------------------------------------------------------------------- - ----------------------------------------------------------------------------------------------------------------------------------------------------------| + ----------------------------------------------------------------------- - ----------------------------------------------------------------------------------------------------------------------------------------------------------|)
5 2 2 \ \ 5 2 2 / / \5 \ 5 2 2 / 2 2 /
Intervalos de crecimiento y decrecimiento de la función:Hallemos los intervalos donde la función crece y decrece y también los puntos mínimos y máximos de la función, para lo cual miramos cómo se comporta la función en los extremos con desviación mínima del extremo:
Puntos mínimos de la función:
$$x_{1} = - \frac{1}{5} + \frac{\sqrt{- \frac{7}{50 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}}} - \frac{6}{25} + 2 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}}}}{2} + \frac{\sqrt{- 2 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}} - \frac{12}{25} + \frac{7}{50 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}}} + \frac{244}{125 \sqrt{- \frac{7}{50 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}}} - \frac{6}{25} + 2 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}}}}}}{2}$$
Puntos máximos de la función:
$$x_{1} = - \frac{\sqrt{- 2 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}} - \frac{12}{25} + \frac{7}{50 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}}} + \frac{244}{125 \sqrt{- \frac{7}{50 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}}} - \frac{6}{25} + 2 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}}}}}}{2} - \frac{1}{5} + \frac{\sqrt{- \frac{7}{50 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}}} - \frac{6}{25} + 2 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}}}}{2}$$
Decrece en los intervalos
$$\left(-\infty, - \frac{\sqrt{- 2 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}} - \frac{12}{25} + \frac{7}{50 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}}} + \frac{244}{125 \sqrt{- \frac{7}{50 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}}} - \frac{6}{25} + 2 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}}}}}}{2} - \frac{1}{5} + \frac{\sqrt{- \frac{7}{50 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}}} - \frac{6}{25} + 2 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}}}}{2}\right] \cup \left[- \frac{1}{5} + \frac{\sqrt{- \frac{7}{50 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}}} - \frac{6}{25} + 2 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}}}}{2} + \frac{\sqrt{- 2 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}} - \frac{12}{25} + \frac{7}{50 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}}} + \frac{244}{125 \sqrt{- \frac{7}{50 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}}} - \frac{6}{25} + 2 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}}}}}}{2}, \infty\right)$$
Crece en los intervalos
$$\left[- \frac{\sqrt{- 2 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}} - \frac{12}{25} + \frac{7}{50 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}}} + \frac{244}{125 \sqrt{- \frac{7}{50 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}}} - \frac{6}{25} + 2 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}}}}}}{2} - \frac{1}{5} + \frac{\sqrt{- \frac{7}{50 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}}} - \frac{6}{25} + 2 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}}}}{2}, - \frac{1}{5} + \frac{\sqrt{- \frac{7}{50 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}}} - \frac{6}{25} + 2 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}}}}{2} + \frac{\sqrt{- 2 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}} - \frac{12}{25} + \frac{7}{50 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}}} + \frac{244}{125 \sqrt{- \frac{7}{50 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}}} - \frac{6}{25} + 2 \sqrt[3]{\frac{73}{1000} + \frac{\sqrt{1418}}{500}}}}}}{2}\right]$$