hasil turunan trigonometri berikut adalah f = cos x/2x

[tex] \frac{d}{dx} \frac{ \cos(x) }{2x} = \frac{2x(\frac{d}{dx} \cos(x)) - \cos(x)(\frac{d}{dx}2x) }{(2x)^{2} } [/tex]
[tex] = \frac{ - 2x \sin(x) - 2 \cos(x) }{4 {x}^{2} } [/tex]
[tex] =-\frac{ x \sin(x) + \cos(x) }{2 {x}^{2} } [/tex]