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$$4 x^{3} - 10 x - \frac{4 \left(x - 2\right)}{\left(x + 1\right)^{2}} + \frac{4}{x + 1} = 0$$
Resolvermos esta ecuaciónRaíces de esta ecuación
$$x_{1} = -2$$
$$x_{2} = - \frac{\sqrt{- 2 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}} - \frac{9}{8 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}}} + \frac{4}{\sqrt{1 + \frac{9}{8 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}}} + 2 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}}}} + 2}}{2} + \frac{\sqrt{1 + \frac{9}{8 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}}} + 2 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}}}}{2}$$
$$x_{3} = \frac{\sqrt{- 2 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}} - \frac{9}{8 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}}} + \frac{4}{\sqrt{1 + \frac{9}{8 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}}} + 2 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}}}} + 2}}{2} + \frac{\sqrt{1 + \frac{9}{8 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}}} + 2 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}}}}{2}$$
Signos de extremos en los puntos:
(-2, 12)
/ _______________________________________________________________________________________________________________________\
4 2 | / _______________ |
_______________________________________________________________________________________________________________________ / _______________________________________________________________________________________________________________________\ / _______________________________________________________________________________________________________________________\ | / / ____ |
/ _______________ | / _______________ | | / _______________ | | / / 39 3*\/ 22 4 9 |
/ / ____ | / / ____ | | / / ____ | | / 2 - 2*3 / -- + -------- + --------------------------------------------------------------- - ---------------------- |
/ / 39 3*\/ 22 4 9 | / / 39 3*\/ 22 4 9 | | / / 39 3*\/ 22 4 9 | | _____________________________________________________ / \/ 64 32 _____________________________________________________ _______________ |
/ 2 - 2*3 / -- + -------- + --------------------------------------------------------------- - ---------------------- | / 2 - 2*3 / -- + -------- + --------------------------------------------------------------- - ---------------------- | | / 2 - 2*3 / -- + -------- + --------------------------------------------------------------- - ---------------------- | | / _______________ / / _______________ / ____ |
_____________________________________________________ / \/ 64 32 _____________________________________________________ _______________ | _____________________________________________________ / \/ 64 32 _____________________________________________________ _______________ | | _____________________________________________________ / \/ 64 32 _____________________________________________________ _______________ | | / / ____ / / / ____ / 39 3*\/ 22 |
/ _______________ / / _______________ / ____ | / _______________ / / _______________ / ____ | | / _______________ / / _______________ / ____ | | / / 39 3*\/ 22 9 / / / 39 3*\/ 22 9 8*3 / -- + -------- |
/ / ____ / / / ____ / 39 3*\/ 22 | / / ____ / / / ____ / 39 3*\/ 22 | | / / ____ / / / ____ / 39 3*\/ 22 | | / 1 + 2*3 / -- + -------- + ---------------------- / / 1 + 2*3 / -- + -------- + ---------------------- \/ 64 32 |
/ / 39 3*\/ 22 9 / / / 39 3*\/ 22 9 8*3 / -- + -------- | / / 39 3*\/ 22 9 / / / 39 3*\/ 22 9 8*3 / -- + -------- | | / / 39 3*\/ 22 9 / / / 39 3*\/ 22 9 8*3 / -- + -------- | | / \/ 64 32 _______________ / / \/ 64 32 _______________ |
/ 1 + 2*3 / -- + -------- + ---------------------- / / 1 + 2*3 / -- + -------- + ---------------------- \/ 64 32 | / 1 + 2*3 / -- + -------- + ---------------------- / / 1 + 2*3 / -- + -------- + ---------------------- \/ 64 32 | | / 1 + 2*3 / -- + -------- + ---------------------- / / 1 + 2*3 / -- + -------- + ---------------------- \/ 64 32 | | / / ____ / / / ____ |
/ \/ 64 32 _______________ / / \/ 64 32 _______________ | / \/ 64 32 _______________ / / \/ 64 32 _______________ | | / \/ 64 32 _______________ / / \/ 64 32 _______________ | | / / 39 3*\/ 22 / / / 39 3*\/ 22 |
/ / ____ / / / ____ | / / ____ / / / ____ | | / / ____ / / / ____ | | / 8*3 / -- + -------- / / 8*3 / -- + -------- |
/ / 39 3*\/ 22 / / / 39 3*\/ 22 | / / 39 3*\/ 22 / / / 39 3*\/ 22 | | / / 39 3*\/ 22 / / / 39 3*\/ 22 | | \/ \/ 64 32 \/ \/ \/ 64 32 |
/ 8*3 / -- + -------- / / 8*3 / -- + -------- | / 8*3 / -- + -------- / / 8*3 / -- + -------- | | / 8*3 / -- + -------- / / 8*3 / -- + -------- | 4*|-2 + --------------------------------------------------------------- - --------------------------------------------------------------------------------------------------------------------------------------|
\/ \/ 64 32 \/ \/ \/ 64 32 |\/ \/ 64 32 \/ \/ \/ 64 32 | |\/ \/ 64 32 \/ \/ \/ 64 32 | \ 2 2 /
(--------------------------------------------------------------- - --------------------------------------------------------------------------------------------------------------------------------------, |--------------------------------------------------------------- - --------------------------------------------------------------------------------------------------------------------------------------| - 5*|--------------------------------------------------------------- - --------------------------------------------------------------------------------------------------------------------------------------| + -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------)
2 2 \ 2 2 / \ 2 2 / _______________________________________________________________________________________________________________________
/ _______________
/ / ____
/ / 39 3*\/ 22 4 9
/ 2 - 2*3 / -- + -------- + --------------------------------------------------------------- - ----------------------
_____________________________________________________ / \/ 64 32 _____________________________________________________ _______________
/ _______________ / / _______________ / ____
/ / ____ / / / ____ / 39 3*\/ 22
/ / 39 3*\/ 22 9 / / / 39 3*\/ 22 9 8*3 / -- + --------
/ 1 + 2*3 / -- + -------- + ---------------------- / / 1 + 2*3 / -- + -------- + ---------------------- \/ 64 32
/ \/ 64 32 _______________ / / \/ 64 32 _______________
/ / ____ / / / ____
/ / 39 3*\/ 22 / / / 39 3*\/ 22
/ 8*3 / -- + -------- / / 8*3 / -- + --------
\/ \/ 64 32 \/ \/ \/ 64 32
1 + --------------------------------------------------------------- - --------------------------------------------------------------------------------------------------------------------------------------
2 2
/ _______________________________________________________________________________________________________________________\
4 2 | / _______________ |
_______________________________________________________________________________________________________________________ / _______________________________________________________________________________________________________________________\ / _______________________________________________________________________________________________________________________\ | / / ____ |
/ _______________ | / _______________ | | / _______________ | | / / 39 3*\/ 22 4 9 |
/ / ____ | / / ____ | | / / ____ | | / 2 - 2*3 / -- + -------- + --------------------------------------------------------------- - ---------------------- |
/ / 39 3*\/ 22 4 9 | / / 39 3*\/ 22 4 9 | | / / 39 3*\/ 22 4 9 | | _____________________________________________________ / \/ 64 32 _____________________________________________________ _______________ |
/ 2 - 2*3 / -- + -------- + --------------------------------------------------------------- - ---------------------- | / 2 - 2*3 / -- + -------- + --------------------------------------------------------------- - ---------------------- | | / 2 - 2*3 / -- + -------- + --------------------------------------------------------------- - ---------------------- | | / _______________ / / _______________ / ____ |
_____________________________________________________ / \/ 64 32 _____________________________________________________ _______________ | _____________________________________________________ / \/ 64 32 _____________________________________________________ _______________ | | _____________________________________________________ / \/ 64 32 _____________________________________________________ _______________ | | / / ____ / / / ____ / 39 3*\/ 22 |
/ _______________ / / _______________ / ____ | / _______________ / / _______________ / ____ | | / _______________ / / _______________ / ____ | | / / 39 3*\/ 22 9 / / / 39 3*\/ 22 9 8*3 / -- + -------- |
/ / ____ / / / ____ / 39 3*\/ 22 | / / ____ / / / ____ / 39 3*\/ 22 | | / / ____ / / / ____ / 39 3*\/ 22 | | / 1 + 2*3 / -- + -------- + ---------------------- / / 1 + 2*3 / -- + -------- + ---------------------- \/ 64 32 |
/ / 39 3*\/ 22 9 / / / 39 3*\/ 22 9 8*3 / -- + -------- | / / 39 3*\/ 22 9 / / / 39 3*\/ 22 9 8*3 / -- + -------- | | / / 39 3*\/ 22 9 / / / 39 3*\/ 22 9 8*3 / -- + -------- | | / \/ 64 32 _______________ / / \/ 64 32 _______________ |
/ 1 + 2*3 / -- + -------- + ---------------------- / / 1 + 2*3 / -- + -------- + ---------------------- \/ 64 32 | / 1 + 2*3 / -- + -------- + ---------------------- / / 1 + 2*3 / -- + -------- + ---------------------- \/ 64 32 | | / 1 + 2*3 / -- + -------- + ---------------------- / / 1 + 2*3 / -- + -------- + ---------------------- \/ 64 32 | | / / ____ / / / ____ |
/ \/ 64 32 _______________ / / \/ 64 32 _______________ | / \/ 64 32 _______________ / / \/ 64 32 _______________ | | / \/ 64 32 _______________ / / \/ 64 32 _______________ | | / / 39 3*\/ 22 / / / 39 3*\/ 22 |
/ / ____ / / / ____ | / / ____ / / / ____ | | / / ____ / / / ____ | | / 8*3 / -- + -------- / / 8*3 / -- + -------- |
/ / 39 3*\/ 22 / / / 39 3*\/ 22 | / / 39 3*\/ 22 / / / 39 3*\/ 22 | | / / 39 3*\/ 22 / / / 39 3*\/ 22 | | \/ \/ 64 32 \/ \/ \/ 64 32 |
/ 8*3 / -- + -------- / / 8*3 / -- + -------- | / 8*3 / -- + -------- / / 8*3 / -- + -------- | | / 8*3 / -- + -------- / / 8*3 / -- + -------- | 4*|-2 + --------------------------------------------------------------- + --------------------------------------------------------------------------------------------------------------------------------------|
\/ \/ 64 32 \/ \/ \/ 64 32 |\/ \/ 64 32 \/ \/ \/ 64 32 | |\/ \/ 64 32 \/ \/ \/ 64 32 | \ 2 2 /
(--------------------------------------------------------------- + --------------------------------------------------------------------------------------------------------------------------------------, |--------------------------------------------------------------- + --------------------------------------------------------------------------------------------------------------------------------------| - 5*|--------------------------------------------------------------- + --------------------------------------------------------------------------------------------------------------------------------------| + -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------)
2 2 \ 2 2 / \ 2 2 / _______________________________________________________________________________________________________________________
/ _______________
/ / ____
/ / 39 3*\/ 22 4 9
/ 2 - 2*3 / -- + -------- + --------------------------------------------------------------- - ----------------------
_____________________________________________________ / \/ 64 32 _____________________________________________________ _______________
/ _______________ / / _______________ / ____
/ / ____ / / / ____ / 39 3*\/ 22
/ / 39 3*\/ 22 9 / / / 39 3*\/ 22 9 8*3 / -- + --------
/ 1 + 2*3 / -- + -------- + ---------------------- / / 1 + 2*3 / -- + -------- + ---------------------- \/ 64 32
/ \/ 64 32 _______________ / / \/ 64 32 _______________
/ / ____ / / / ____
/ / 39 3*\/ 22 / / / 39 3*\/ 22
/ 8*3 / -- + -------- / / 8*3 / -- + --------
\/ \/ 64 32 \/ \/ \/ 64 32
1 + --------------------------------------------------------------- + --------------------------------------------------------------------------------------------------------------------------------------
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:
$$x_{1} = -2$$
$$x_{2} = \frac{\sqrt{- 2 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}} - \frac{9}{8 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}}} + \frac{4}{\sqrt{1 + \frac{9}{8 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}}} + 2 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}}}} + 2}}{2} + \frac{\sqrt{1 + \frac{9}{8 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}}} + 2 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}}}}{2}$$
Puntos máximos de la función:
$$x_{2} = - \frac{\sqrt{- 2 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}} - \frac{9}{8 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}}} + \frac{4}{\sqrt{1 + \frac{9}{8 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}}} + 2 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}}}} + 2}}{2} + \frac{\sqrt{1 + \frac{9}{8 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}}} + 2 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}}}}{2}$$
Decrece en los intervalos
$$\left[-2, - \frac{\sqrt{- 2 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}} - \frac{9}{8 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}}} + \frac{4}{\sqrt{1 + \frac{9}{8 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}}} + 2 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}}}} + 2}}{2} + \frac{\sqrt{1 + \frac{9}{8 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}}} + 2 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}}}}{2}\right] \cup \left[\frac{\sqrt{- 2 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}} - \frac{9}{8 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}}} + \frac{4}{\sqrt{1 + \frac{9}{8 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}}} + 2 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}}}} + 2}}{2} + \frac{\sqrt{1 + \frac{9}{8 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}}} + 2 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}}}}{2}, \infty\right)$$
Crece en los intervalos
$$\left(-\infty, -2\right] \cup \left[- \frac{\sqrt{- 2 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}} - \frac{9}{8 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}}} + \frac{4}{\sqrt{1 + \frac{9}{8 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}}} + 2 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}}}} + 2}}{2} + \frac{\sqrt{1 + \frac{9}{8 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}}} + 2 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}}}}{2}, \frac{\sqrt{- 2 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}} - \frac{9}{8 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}}} + \frac{4}{\sqrt{1 + \frac{9}{8 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}}} + 2 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}}}} + 2}}{2} + \frac{\sqrt{1 + \frac{9}{8 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}}} + 2 \sqrt[3]{\frac{3 \sqrt{22}}{32} + \frac{39}{64}}}}{2}\right]$$