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$$- \frac{x \left(\left(x^{3} + 2 x\right) - 5\right)}{\left(x^{2} - 4\right)^{\frac{3}{2}}} + \frac{3 x^{2} + 2}{\sqrt{x^{2} - 4}} = 0$$
Resolvermos esta ecuaciónRaíces de esta ecuación
$$x_{1} = - \frac{\sqrt{- \frac{2}{3 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}}} + 2 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}} + 4}}{2} + \frac{\sqrt{- 2 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}} + \frac{2}{3 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}}} + 8 + \frac{5}{\sqrt{- \frac{2}{3 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}}} + 2 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}} + 4}}}}{2}$$
$$x_{2} = - \frac{\sqrt{- 2 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}} + \frac{2}{3 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}}} + 8 + \frac{5}{\sqrt{- \frac{2}{3 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}}} + 2 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}} + 4}}}}{2} - \frac{\sqrt{- \frac{2}{3 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}}} + 2 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}} + 4}}{2}$$
Signos de extremos en los puntos:
3
/ _______________________________________________________________________________________________________________________________________________ \
| / _____________________ |
| / / _________ |
| / / 295 \/ 7061313 5 2 |
| / 8 - 2*3 / - --- + ----------- + --------------------------------------------------------------------------- + ---------------------------- |
| / \/ 64 576 _________________________________________________________________ _____________________ _________________________________________________________________|
| / / _____________________ / _________ / _____________________ |
| / / / _________ / 295 \/ 7061313 / / _________ |
| / / / 295 \/ 7061313 2 3*3 / - --- + ----------- / / 295 \/ 7061313 2 |
| / / 4 + 2*3 / - --- + ----------- - ---------------------------- \/ 64 576 / 4 + 2*3 / - --- + ----------- - ---------------------------- |
| / / \/ 64 576 _____________________ / \/ 64 576 _____________________ |
_______________________________________________________________________________________________________________________________________________ | / / / _________ / / _________ | _______________________________________________________________________________________________________________________________________________ _________________________________________________________________
/ _____________________ | / / / 295 \/ 7061313 / / 295 \/ 7061313 | / _____________________ / _____________________
/ / _________ | / / 3*3 / - --- + ----------- / 3*3 / - --- + ----------- | / / _________ / / _________
/ / 295 \/ 7061313 5 2 |\/ \/ \/ 64 576 \/ \/ 64 576 | / / 295 \/ 7061313 5 2 / / 295 \/ 7061313 2
/ 8 - 2*3 / - --- + ----------- + --------------------------------------------------------------------------- + ---------------------------- -5 + |-------------------------------------------------------------------------------------------------------------------------------------------------------------- - ---------------------------------------------------------------------------| + / 8 - 2*3 / - --- + ----------- + --------------------------------------------------------------------------- + ---------------------------- - / 4 + 2*3 / - --- + ----------- - ----------------------------
/ \/ 64 576 _________________________________________________________________ _____________________ _________________________________________________________________ \ 2 2 / / \/ 64 576 _________________________________________________________________ _____________________ / \/ 64 576 _____________________
/ / _____________________ / _________ / _____________________ / / _____________________ / _________ / / _________
/ / / _________ / 295 \/ 7061313 / / _________ / / / _________ / 295 \/ 7061313 / / 295 \/ 7061313
/ / / 295 \/ 7061313 2 3*3 / - --- + ----------- / / 295 \/ 7061313 2 / / / 295 \/ 7061313 2 3*3 / - --- + ----------- / 3*3 / - --- + -----------
/ / 4 + 2*3 / - --- + ----------- - ---------------------------- \/ 64 576 / 4 + 2*3 / - --- + ----------- - ---------------------------- / / 4 + 2*3 / - --- + ----------- - ---------------------------- \/ 64 576 \/ \/ 64 576
/ / \/ 64 576 _____________________ / \/ 64 576 _____________________ / / \/ 64 576 _____________________
/ / / _________ / / _________ / / / _________
/ / / 295 \/ 7061313 / / 295 \/ 7061313 / / / 295 \/ 7061313
/ / 3*3 / - --- + ----------- / 3*3 / - --- + ----------- / / 3*3 / - --- + -----------
\/ \/ \/ 64 576 \/ \/ 64 576 \/ \/ \/ 64 576
(-------------------------------------------------------------------------------------------------------------------------------------------------------------- - ---------------------------------------------------------------------------, ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------)
2 2 ______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
/ 2
/ / _______________________________________________________________________________________________________________________________________________ \
/ | / _____________________ |
/ | / / _________ |
/ | / / 295 \/ 7061313 5 2 |
/ | / 8 - 2*3 / - --- + ----------- + --------------------------------------------------------------------------- + ---------------------------- |
/ | / \/ 64 576 _________________________________________________________________ _____________________ _________________________________________________________________|
/ | / / _____________________ / _________ / _____________________ |
/ | / / / _________ / 295 \/ 7061313 / / _________ |
/ | / / / 295 \/ 7061313 2 3*3 / - --- + ----------- / / 295 \/ 7061313 2 |
/ | / / 4 + 2*3 / - --- + ----------- - ---------------------------- \/ 64 576 / 4 + 2*3 / - --- + ----------- - ---------------------------- |
/ | / / \/ 64 576 _____________________ / \/ 64 576 _____________________ |
/ | / / / _________ / / _________ |
/ | / / / 295 \/ 7061313 / / 295 \/ 7061313 |
/ | / / 3*3 / - --- + ----------- / 3*3 / - --- + ----------- |
/ |\/ \/ \/ 64 576 \/ \/ 64 576 |
/ -4 + |-------------------------------------------------------------------------------------------------------------------------------------------------------------- - ---------------------------------------------------------------------------|
\/ \ 2 2 /
3
/ _______________________________________________________________________________________________________________________________________________\
| / _____________________ |
| / / _________ |
| / / 295 \/ 7061313 5 2 |
| / 8 - 2*3 / - --- + ----------- + --------------------------------------------------------------------------- + ---------------------------- |
| _________________________________________________________________ / \/ 64 576 _________________________________________________________________ _____________________ |
| / _____________________ / / _____________________ / _________ |
| / / _________ / / / _________ / 295 \/ 7061313 |
| / / 295 \/ 7061313 2 / / / 295 \/ 7061313 2 3*3 / - --- + ----------- |
| / 4 + 2*3 / - --- + ----------- - ---------------------------- / / 4 + 2*3 / - --- + ----------- - ---------------------------- \/ 64 576 |
| / \/ 64 576 _____________________ / / \/ 64 576 _____________________ |
_______________________________________________________________________________________________________________________________________________ | / / _________ / / / _________ | _________________________________________________________________ _______________________________________________________________________________________________________________________________________________
/ _____________________ | / / 295 \/ 7061313 / / / 295 \/ 7061313 | / _____________________ / _____________________
/ / _________ | / 3*3 / - --- + ----------- / / 3*3 / - --- + ----------- | / / _________ / / _________
/ / 295 \/ 7061313 5 2 | \/ \/ 64 576 \/ \/ \/ 64 576 | / / 295 \/ 7061313 2 / / 295 \/ 7061313 5 2
/ 8 - 2*3 / - --- + ----------- + --------------------------------------------------------------------------- + ---------------------------- -5 + |- --------------------------------------------------------------------------- - --------------------------------------------------------------------------------------------------------------------------------------------------------------| - / 4 + 2*3 / - --- + ----------- - ---------------------------- - / 8 - 2*3 / - --- + ----------- + --------------------------------------------------------------------------- + ----------------------------
_________________________________________________________________ / \/ 64 576 _________________________________________________________________ _____________________ \ 2 2 / / \/ 64 576 _____________________ / \/ 64 576 _________________________________________________________________ _____________________
/ _____________________ / / _____________________ / _________ / / _________ / / _____________________ / _________
/ / _________ / / / _________ / 295 \/ 7061313 / / 295 \/ 7061313 / / / _________ / 295 \/ 7061313
/ / 295 \/ 7061313 2 / / / 295 \/ 7061313 2 3*3 / - --- + ----------- / 3*3 / - --- + ----------- / / / 295 \/ 7061313 2 3*3 / - --- + -----------
/ 4 + 2*3 / - --- + ----------- - ---------------------------- / / 4 + 2*3 / - --- + ----------- - ---------------------------- \/ 64 576 \/ \/ 64 576 / / 4 + 2*3 / - --- + ----------- - ---------------------------- \/ 64 576
/ \/ 64 576 _____________________ / / \/ 64 576 _____________________ / / \/ 64 576 _____________________
/ / _________ / / / _________ / / / _________
/ / 295 \/ 7061313 / / / 295 \/ 7061313 / / / 295 \/ 7061313
/ 3*3 / - --- + ----------- / / 3*3 / - --- + ----------- / / 3*3 / - --- + -----------
\/ \/ 64 576 \/ \/ \/ 64 576 \/ \/ \/ 64 576
(- --------------------------------------------------------------------------- - --------------------------------------------------------------------------------------------------------------------------------------------------------------, -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------)
2 2 ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
/ 2
/ / _______________________________________________________________________________________________________________________________________________\
/ | / _____________________ |
/ | / / _________ |
/ | / / 295 \/ 7061313 5 2 |
/ | / 8 - 2*3 / - --- + ----------- + --------------------------------------------------------------------------- + ---------------------------- |
/ | _________________________________________________________________ / \/ 64 576 _________________________________________________________________ _____________________ |
/ | / _____________________ / / _____________________ / _________ |
/ | / / _________ / / / _________ / 295 \/ 7061313 |
/ | / / 295 \/ 7061313 2 / / / 295 \/ 7061313 2 3*3 / - --- + ----------- |
/ | / 4 + 2*3 / - --- + ----------- - ---------------------------- / / 4 + 2*3 / - --- + ----------- - ---------------------------- \/ 64 576 |
/ | / \/ 64 576 _____________________ / / \/ 64 576 _____________________ |
/ | / / _________ / / / _________ |
/ | / / 295 \/ 7061313 / / / 295 \/ 7061313 |
/ | / 3*3 / - --- + ----------- / / 3*3 / - --- + ----------- |
/ | \/ \/ 64 576 \/ \/ \/ 64 576 |
/ -4 + |- --------------------------------------------------------------------------- - --------------------------------------------------------------------------------------------------------------------------------------------------------------|
\/ \ 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:
$$x_{1} = - \frac{\sqrt{\left|{- \frac{2}{3 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}}} + 2 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}} + 4}\right|}}{2} + \frac{\sqrt{- 2 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}} + \frac{2}{3 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}}} + 8 + \frac{5}{\sqrt{\left|{- \frac{2}{3 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}}} + 2 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}} + 4}\right|}}}}{2}$$
Puntos máximos de la función:
$$x_{1} = - \frac{\sqrt{- 2 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}} + \frac{2}{3 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}}} + 8 + \frac{5}{\sqrt{\left|{- \frac{2}{3 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}}} + 2 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}} + 4}\right|}}}}{2} - \frac{\sqrt{\left|{- \frac{2}{3 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}}} + 2 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}} + 4}\right|}}{2}$$
Decrece en los intervalos
$$\left(-\infty, - \frac{\sqrt{- 2 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}} + \frac{2}{3 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}}} + 8 + \frac{5}{\sqrt{\left|{- \frac{2}{3 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}}} + 2 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}} + 4}\right|}}}}{2} - \frac{\sqrt{\left|{- \frac{2}{3 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}}} + 2 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}} + 4}\right|}}{2}\right] \cup \left[- \frac{\sqrt{\left|{- \frac{2}{3 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}}} + 2 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}} + 4}\right|}}{2} + \frac{\sqrt{- 2 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}} + \frac{2}{3 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}}} + 8 + \frac{5}{\sqrt{\left|{- \frac{2}{3 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}}} + 2 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}} + 4}\right|}}}}{2}, \infty\right)$$
Crece en los intervalos
$$\left[- \frac{\sqrt{- 2 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}} + \frac{2}{3 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}}} + 8 + \frac{5}{\sqrt{\left|{- \frac{2}{3 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}}} + 2 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}} + 4}\right|}}}}{2} - \frac{\sqrt{\left|{- \frac{2}{3 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}}} + 2 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}} + 4}\right|}}{2}, - \frac{\sqrt{\left|{- \frac{2}{3 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}}} + 2 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}} + 4}\right|}}{2} + \frac{\sqrt{- 2 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}} + \frac{2}{3 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}}} + 8 + \frac{5}{\sqrt{\left|{- \frac{2}{3 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}}} + 2 \sqrt[3]{- \frac{295}{64} + \frac{\sqrt{7061313}}{576}} + 4}\right|}}}}{2}\right]$$