Derivatan av $$$\sin{\left(u \right)} - \cos{\left(u \right)}$$$
Relaterade kalkylatorer: Kalkylator för logaritmisk derivering, Räknare för implicit derivering med steg
Din inmatning
Bestäm $$$\frac{d}{du} \left(\sin{\left(u \right)} - \cos{\left(u \right)}\right)$$$.
Lösning
Derivatan av en summa/differens är summan/differensen av derivatorna:
$${\color{red}\left(\frac{d}{du} \left(\sin{\left(u \right)} - \cos{\left(u \right)}\right)\right)} = {\color{red}\left(\frac{d}{du} \left(\sin{\left(u \right)}\right) - \frac{d}{du} \left(\cos{\left(u \right)}\right)\right)}$$Derivatan av sinus är $$$\frac{d}{du} \left(\sin{\left(u \right)}\right) = \cos{\left(u \right)}$$$:
$${\color{red}\left(\frac{d}{du} \left(\sin{\left(u \right)}\right)\right)} - \frac{d}{du} \left(\cos{\left(u \right)}\right) = {\color{red}\left(\cos{\left(u \right)}\right)} - \frac{d}{du} \left(\cos{\left(u \right)}\right)$$Derivatan av cosinus är $$$\frac{d}{du} \left(\cos{\left(u \right)}\right) = - \sin{\left(u \right)}$$$:
$$\cos{\left(u \right)} - {\color{red}\left(\frac{d}{du} \left(\cos{\left(u \right)}\right)\right)} = \cos{\left(u \right)} - {\color{red}\left(- \sin{\left(u \right)}\right)}$$Förenkla:
$$\sin{\left(u \right)} + \cos{\left(u \right)} = \sqrt{2} \sin{\left(u + \frac{\pi}{4} \right)}$$Alltså, $$$\frac{d}{du} \left(\sin{\left(u \right)} - \cos{\left(u \right)}\right) = \sqrt{2} \sin{\left(u + \frac{\pi}{4} \right)}$$$.
Svar
$$$\frac{d}{du} \left(\sin{\left(u \right)} - \cos{\left(u \right)}\right) = \sqrt{2} \sin{\left(u + \frac{\pi}{4} \right)}$$$A