The derivative of sinx/x is equal to (xcosx -sinx)/x2. Here we will learn how to differentiate sinx/x with respect to x.
The derivative formula of sinx/x is given by
$\dfrac{d}{dx}(\dfrac{\sin x}{x})$ = $\dfrac{x\cos x -\sin x}{x^2}$.
Find the Derivative of sinx/x
As sinx/x is a quotient function, to find the derivative of sinx/x we will use the quotient rule of derivatives. By the rule, the derivative of $\dfrac{f}{g}$ is given by
$\big(\dfrac{f}{g}\big)’$ = $\dfrac{gf’-fg’}{g^2}$
where $’$ denotes the first order derivative with respect to x.
Put f=sinx and g=x, the derivative of sinx/x is equal to
$\big(\dfrac{\sin x}{x}\big)’$ = $\dfrac{x \cdot (\sin x)’-\sin x \cdot (x)’}{x^2}$
= $\dfrac{x \cdot \cos x-\sin x \cdot 1}{x^2}$ as the derivative of sinx is cosx and the derivative of x is 1.
= $\dfrac{x \cdot \cos x-\sin x \cdot 1}{x^2}$
= $\dfrac{x\cos x -\sin x}{x^2}$.
So the derivative of sinx/x is (xcosx -sinx)/x2 and it is obtained by the quotient rule of derivatives.
ALSO READ:
Question-Answer on Derivative of sinx/x
Question: What is the derivative of sinx/x at x=1?
Answer:
From above, the derivative of sinx/x at x=1 is equal to
[(sinx/x)$’$] = [(xcosx -sinx)/x2]x=1
= (1 ⋅ cos1 -sin1)/12
= cos1 -sin1.
So the derivative of sinx/x at the point x=1 is equal to cos1 -sin1.
Have You Read These Derivatives?
FAQs
Q1: What is the derivative of sinx/x?
Answer: The derivative of sinx/x, denoted by d/dx(sinx/x), is equal to (xcosx -sinx)/x2.