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Funktion $$$\ln\left(x^{2}\right)$$$ derivaatta
Aiheeseen liittyvät laskurit: Logaritmisen derivoinnin laskin, Vaiheittainen implisiittisen derivoinnin laskin
Syötteesi
Määritä $$$\frac{d}{dx} \left(\ln\left(x^{2}\right)\right)$$$.
Ratkaisu
Funktio $$$\ln\left(x^{2}\right)$$$ on kahden funktion $$$f{\left(u \right)} = \ln\left(u\right)$$$ ja $$$g{\left(x \right)} = x^{2}$$$ yhdistelmä $$$f{\left(g{\left(x \right)} \right)}$$$.
Sovella ketjusääntöä $$$\frac{d}{dx} \left(f{\left(g{\left(x \right)} \right)}\right) = \frac{d}{du} \left(f{\left(u \right)}\right) \frac{d}{dx} \left(g{\left(x \right)}\right)$$$:
$${\color{red}\left(\frac{d}{dx} \left(\ln\left(x^{2}\right)\right)\right)} = {\color{red}\left(\frac{d}{du} \left(\ln\left(u\right)\right) \frac{d}{dx} \left(x^{2}\right)\right)}$$Luonnollisen logaritmin derivaatta on $$$\frac{d}{du} \left(\ln\left(u\right)\right) = \frac{1}{u}$$$:
$${\color{red}\left(\frac{d}{du} \left(\ln\left(u\right)\right)\right)} \frac{d}{dx} \left(x^{2}\right) = {\color{red}\left(\frac{1}{u}\right)} \frac{d}{dx} \left(x^{2}\right)$$Palaa alkuperäiseen muuttujaan:
$$\frac{\frac{d}{dx} \left(x^{2}\right)}{{\color{red}\left(u\right)}} = \frac{\frac{d}{dx} \left(x^{2}\right)}{{\color{red}\left(x^{2}\right)}}$$Sovella potenssisääntöä $$$\frac{d}{dx} \left(x^{n}\right) = n x^{n - 1}$$$, kun $$$n = 2$$$:
$$\frac{{\color{red}\left(\frac{d}{dx} \left(x^{2}\right)\right)}}{x^{2}} = \frac{{\color{red}\left(2 x\right)}}{x^{2}}$$Näin ollen, $$$\frac{d}{dx} \left(\ln\left(x^{2}\right)\right) = \frac{2}{x}$$$.
Vastaus
$$$\frac{d}{dx} \left(\ln\left(x^{2}\right)\right) = \frac{2}{x}$$$A