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$$- 2 e^{2 x} - e^{x} + 2 e^{- 2 x} = 0$$
Resolvermos esta ecuaciónRaíces de esta ecuación
$$x_{1} = \log{\left(- \frac{1}{8} - \frac{\sqrt{- \frac{2}{3 \sqrt[3]{- \frac{1}{64} + \frac{\sqrt{12369}}{576}}} + \frac{1}{16} + 2 \sqrt[3]{- \frac{1}{64} + \frac{\sqrt{12369}}{576}}}}{2} + \frac{\sqrt{- 2 \sqrt[3]{- \frac{1}{64} + \frac{\sqrt{12369}}{576}} + \frac{1}{8} + \frac{2}{3 \sqrt[3]{- \frac{1}{64} + \frac{\sqrt{12369}}{576}}} + \frac{1}{32 \sqrt{- \frac{2}{3 \sqrt[3]{- \frac{1}{64} + \frac{\sqrt{12369}}{576}}} + \frac{1}{16} + 2 \sqrt[3]{- \frac{1}{64} + \frac{\sqrt{12369}}{576}}}}}}{2} \right)}$$
Signos de extremos en los puntos:
2
/ _______________________________________________________________________________________________________________________________________ \ / _______________________________________________________________________________________________________________________________________ \ _______________________________________________________________________________________________________________________________________
| / __________________ | | / __________________ | / __________________
| / / _______ | | / / _______ | / / _______
| / 1 / 1 \/ 12369 1 2 | | / 1 / 1 \/ 12369 1 2 | / 1 / 1 \/ 12369 1 2
| / - - 2*3 / - -- + --------- + ------------------------------------------------------------------------- + ------------------------- | | / - - 2*3 / - -- + --------- + ------------------------------------------------------------------------- + ------------------------- | / - - 2*3 / - -- + --------- + ------------------------------------------------------------------------- + -------------------------
| / 8 \/ 64 576 ____________________________________________________________ __________________ ____________________________________________________________| ____________________________________________________________ | / 8 \/ 64 576 ____________________________________________________________ __________________ ____________________________________________________________| / 8 \/ 64 576 ____________________________________________________________ __________________
| / / __________________ / _______ / __________________ | / __________________ | / / __________________ / _______ / __________________ | / / __________________ / _______
| / / / _______ / 1 \/ 12369 / / _______ | / / _______ | / / / _______ / 1 \/ 12369 / / _______ | / / / _______ / 1 \/ 12369
| / / 1 / 1 \/ 12369 2 3*3 / - -- + --------- / 1 / 1 \/ 12369 2 | / 1 / 1 \/ 12369 2 | / / 1 / 1 \/ 12369 2 3*3 / - -- + --------- / 1 / 1 \/ 12369 2 | / / 1 / 1 \/ 12369 2 3*3 / - -- + ---------
| / 32* / -- + 2*3 / - -- + --------- - ------------------------- \/ 64 576 / -- + 2*3 / - -- + --------- - ------------------------- | / -- + 2*3 / - -- + --------- - ------------------------- | / 32* / -- + 2*3 / - -- + --------- - ------------------------- \/ 64 576 / -- + 2*3 / - -- + --------- - ------------------------- | / 32* / -- + 2*3 / - -- + --------- - ------------------------- \/ 64 576
| / / 16 \/ 64 576 __________________ / 16 \/ 64 576 __________________ | / 16 \/ 64 576 __________________ | / / 16 \/ 64 576 __________________ / 16 \/ 64 576 __________________ | / / 16 \/ 64 576 __________________
| / / / _______ / / _______ | / / _______ | / / / _______ / / _______ | / / / _______
| / / / 1 \/ 12369 / / 1 \/ 12369 | / / 1 \/ 12369 | / / / 1 \/ 12369 / / 1 \/ 12369 | / / / 1 \/ 12369
| / / 3*3 / - -- + --------- / 3*3 / - -- + --------- | / 3*3 / - -- + --------- | / / 3*3 / - -- + --------- / 3*3 / - -- + --------- | / / 3*3 / - -- + ---------
| 1 \/ \/ \/ 64 576 \/ \/ 64 576 | 1 \/ \/ 64 576 1 | 1 \/ \/ \/ 64 576 \/ \/ 64 576 | \/ \/ \/ 64 576
(log|- - + ------------------------------------------------------------------------------------------------------------------------------------------------------ - ----------------------------------------------------------------------|, - + ---------------------------------------------------------------------- - ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- - |- - + ------------------------------------------------------------------------------------------------------------------------------------------------------ - ----------------------------------------------------------------------| - ------------------------------------------------------------------------------------------------------------------------------------------------------)
\ 8 2 2 / 8 2 2 \ 8 2 2 / 2
/ _______________________________________________________________________________________________________________________________________ \
| / __________________ |
| / / _______ |
| / 1 / 1 \/ 12369 1 2 |
| / - - 2*3 / - -- + --------- + ------------------------------------------------------------------------- + ------------------------- |
| / 8 \/ 64 576 ____________________________________________________________ __________________ ____________________________________________________________|
| / / __________________ / _______ / __________________ |
| / / / _______ / 1 \/ 12369 / / _______ |
| / / 1 / 1 \/ 12369 2 3*3 / - -- + --------- / 1 / 1 \/ 12369 2 |
| / 32* / -- + 2*3 / - -- + --------- - ------------------------- \/ 64 576 / -- + 2*3 / - -- + --------- - ------------------------- |
| / / 16 \/ 64 576 __________________ / 16 \/ 64 576 __________________ |
| / / / _______ / / _______ |
| / / / 1 \/ 12369 / / 1 \/ 12369 |
| / / 3*3 / - -- + --------- / 3*3 / - -- + --------- |
| 1 \/ \/ \/ 64 576 \/ \/ 64 576 |
|- - + ------------------------------------------------------------------------------------------------------------------------------------------------------ - ----------------------------------------------------------------------|
\ 8 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:
La función no tiene puntos mínimos
Puntos máximos de la función:
$$x_{1} = \log{\left(- \frac{1}{8} - \frac{\sqrt{- \frac{2}{3 \sqrt[3]{- \frac{1}{64} + \frac{\sqrt{12369}}{576}}} + \frac{1}{16} + 2 \sqrt[3]{- \frac{1}{64} + \frac{\sqrt{12369}}{576}}}}{2} + \frac{\sqrt{- 2 \sqrt[3]{- \frac{1}{64} + \frac{\sqrt{12369}}{576}} + \frac{1}{8} + \frac{2}{3 \sqrt[3]{- \frac{1}{64} + \frac{\sqrt{12369}}{576}}} + \frac{1}{32 \sqrt{- \frac{2}{3 \sqrt[3]{- \frac{1}{64} + \frac{\sqrt{12369}}{576}}} + \frac{1}{16} + 2 \sqrt[3]{- \frac{1}{64} + \frac{\sqrt{12369}}{576}}}}}}{2} \right)}$$
Decrece en los intervalos
$$\left(-\infty, \log{\left(- \frac{1}{8} - \frac{\sqrt{- \frac{2}{3 \sqrt[3]{- \frac{1}{64} + \frac{\sqrt{12369}}{576}}} + \frac{1}{16} + 2 \sqrt[3]{- \frac{1}{64} + \frac{\sqrt{12369}}{576}}}}{2} + \frac{\sqrt{- 2 \sqrt[3]{- \frac{1}{64} + \frac{\sqrt{12369}}{576}} + \frac{1}{8} + \frac{2}{3 \sqrt[3]{- \frac{1}{64} + \frac{\sqrt{12369}}{576}}} + \frac{1}{32 \sqrt{- \frac{2}{3 \sqrt[3]{- \frac{1}{64} + \frac{\sqrt{12369}}{576}}} + \frac{1}{16} + 2 \sqrt[3]{- \frac{1}{64} + \frac{\sqrt{12369}}{576}}}}}}{2} \right)}\right]$$
Crece en los intervalos
$$\left[\log{\left(- \frac{1}{8} - \frac{\sqrt{- \frac{2}{3 \sqrt[3]{- \frac{1}{64} + \frac{\sqrt{12369}}{576}}} + \frac{1}{16} + 2 \sqrt[3]{- \frac{1}{64} + \frac{\sqrt{12369}}{576}}}}{2} + \frac{\sqrt{- 2 \sqrt[3]{- \frac{1}{64} + \frac{\sqrt{12369}}{576}} + \frac{1}{8} + \frac{2}{3 \sqrt[3]{- \frac{1}{64} + \frac{\sqrt{12369}}{576}}} + \frac{1}{32 \sqrt{- \frac{2}{3 \sqrt[3]{- \frac{1}{64} + \frac{\sqrt{12369}}{576}}} + \frac{1}{16} + 2 \sqrt[3]{- \frac{1}{64} + \frac{\sqrt{12369}}{576}}}}}}{2} \right)}, \infty\right)$$