Toisen derivaatan laskin
Laske toiset derivaatat vaiheittain
Tämä laskin laskee minkä tahansa funktion toisen derivaatan vaiheittain. Lisäksi se laskee toisen derivaatan arvon annetussa pisteessä tarvittaessa.
Aiheeseen liittyvät laskurit: Derivointilaskin, Logaritmisen derivoinnin laskin
Syötteesi
Määritä $$$\frac{d^{2}}{dx^{2}} \left(\sin{\left(5 x \right)}\right)$$$.
Ratkaisu
Laske ensimmäinen derivaatta $$$\frac{d}{dx} \left(\sin{\left(5 x \right)}\right)$$$
Funktio $$$\sin{\left(5 x \right)}$$$ on kahden funktion $$$f{\left(u \right)} = \sin{\left(u \right)}$$$ ja $$$g{\left(x \right)} = 5 x$$$ yhdistelmä $$$f{\left(g{\left(x \right)} \right)}$$$.
Sovella ketjusääntöä $$$\frac{d}{dx} \left(f{\left(g{\left(x \right)} \right)}\right) = \frac{d}{du} \left(f{\left(u \right)}\right) \frac{d}{dx} \left(g{\left(x \right)}\right)$$$:
$${\color{red}\left(\frac{d}{dx} \left(\sin{\left(5 x \right)}\right)\right)} = {\color{red}\left(\frac{d}{du} \left(\sin{\left(u \right)}\right) \frac{d}{dx} \left(5 x\right)\right)}$$Sinin derivaatta on $$$\frac{d}{du} \left(\sin{\left(u \right)}\right) = \cos{\left(u \right)}$$$:
$${\color{red}\left(\frac{d}{du} \left(\sin{\left(u \right)}\right)\right)} \frac{d}{dx} \left(5 x\right) = {\color{red}\left(\cos{\left(u \right)}\right)} \frac{d}{dx} \left(5 x\right)$$Palaa alkuperäiseen muuttujaan:
$$\cos{\left({\color{red}\left(u\right)} \right)} \frac{d}{dx} \left(5 x\right) = \cos{\left({\color{red}\left(5 x\right)} \right)} \frac{d}{dx} \left(5 x\right)$$Sovella vakion kerroinsääntöä $$$\frac{d}{dx} \left(c f{\left(x \right)}\right) = c \frac{d}{dx} \left(f{\left(x \right)}\right)$$$ käyttäen $$$c = 5$$$ ja $$$f{\left(x \right)} = x$$$:
$$\cos{\left(5 x \right)} {\color{red}\left(\frac{d}{dx} \left(5 x\right)\right)} = \cos{\left(5 x \right)} {\color{red}\left(5 \frac{d}{dx} \left(x\right)\right)}$$Sovella potenssisääntöä $$$\frac{d}{dx} \left(x^{n}\right) = n x^{n - 1}$$$ käyttäen $$$n = 1$$$, toisin sanoen, $$$\frac{d}{dx} \left(x\right) = 1$$$:
$$5 \cos{\left(5 x \right)} {\color{red}\left(\frac{d}{dx} \left(x\right)\right)} = 5 \cos{\left(5 x \right)} {\color{red}\left(1\right)}$$Näin ollen, $$$\frac{d}{dx} \left(\sin{\left(5 x \right)}\right) = 5 \cos{\left(5 x \right)}$$$.
Seuraavaksi $$$\frac{d^{2}}{dx^{2}} \left(\sin{\left(5 x \right)}\right) = \frac{d}{dx} \left(5 \cos{\left(5 x \right)}\right)$$$
Sovella vakion kerroinsääntöä $$$\frac{d}{dx} \left(c f{\left(x \right)}\right) = c \frac{d}{dx} \left(f{\left(x \right)}\right)$$$ käyttäen $$$c = 5$$$ ja $$$f{\left(x \right)} = \cos{\left(5 x \right)}$$$:
$${\color{red}\left(\frac{d}{dx} \left(5 \cos{\left(5 x \right)}\right)\right)} = {\color{red}\left(5 \frac{d}{dx} \left(\cos{\left(5 x \right)}\right)\right)}$$Funktio $$$\cos{\left(5 x \right)}$$$ on kahden funktion $$$f{\left(u \right)} = \cos{\left(u \right)}$$$ ja $$$g{\left(x \right)} = 5 x$$$ yhdistelmä $$$f{\left(g{\left(x \right)} \right)}$$$.
Sovella ketjusääntöä $$$\frac{d}{dx} \left(f{\left(g{\left(x \right)} \right)}\right) = \frac{d}{du} \left(f{\left(u \right)}\right) \frac{d}{dx} \left(g{\left(x \right)}\right)$$$:
$$5 {\color{red}\left(\frac{d}{dx} \left(\cos{\left(5 x \right)}\right)\right)} = 5 {\color{red}\left(\frac{d}{du} \left(\cos{\left(u \right)}\right) \frac{d}{dx} \left(5 x\right)\right)}$$Kosinin derivaatta on $$$\frac{d}{du} \left(\cos{\left(u \right)}\right) = - \sin{\left(u \right)}$$$:
$$5 {\color{red}\left(\frac{d}{du} \left(\cos{\left(u \right)}\right)\right)} \frac{d}{dx} \left(5 x\right) = 5 {\color{red}\left(- \sin{\left(u \right)}\right)} \frac{d}{dx} \left(5 x\right)$$Palaa alkuperäiseen muuttujaan:
$$- 5 \sin{\left({\color{red}\left(u\right)} \right)} \frac{d}{dx} \left(5 x\right) = - 5 \sin{\left({\color{red}\left(5 x\right)} \right)} \frac{d}{dx} \left(5 x\right)$$Sovella vakion kerroinsääntöä $$$\frac{d}{dx} \left(c f{\left(x \right)}\right) = c \frac{d}{dx} \left(f{\left(x \right)}\right)$$$ käyttäen $$$c = 5$$$ ja $$$f{\left(x \right)} = x$$$:
$$- 5 \sin{\left(5 x \right)} {\color{red}\left(\frac{d}{dx} \left(5 x\right)\right)} = - 5 \sin{\left(5 x \right)} {\color{red}\left(5 \frac{d}{dx} \left(x\right)\right)}$$Sovella potenssisääntöä $$$\frac{d}{dx} \left(x^{n}\right) = n x^{n - 1}$$$ käyttäen $$$n = 1$$$, toisin sanoen, $$$\frac{d}{dx} \left(x\right) = 1$$$:
$$- 25 \sin{\left(5 x \right)} {\color{red}\left(\frac{d}{dx} \left(x\right)\right)} = - 25 \sin{\left(5 x \right)} {\color{red}\left(1\right)}$$Näin ollen, $$$\frac{d}{dx} \left(5 \cos{\left(5 x \right)}\right) = - 25 \sin{\left(5 x \right)}$$$.
Siispä $$$\frac{d^{2}}{dx^{2}} \left(\sin{\left(5 x \right)}\right) = - 25 \sin{\left(5 x \right)}$$$.
Vastaus
$$$\frac{d^{2}}{dx^{2}} \left(\sin{\left(5 x \right)}\right) = - 25 \sin{\left(5 x \right)}$$$A