Derivative of csc(x)

The derivative of the cosecant is $\dfrac{d}{dx}\csc x = -\csc x\cot x = -\dfrac{\cos x}{\sin^2 x}$, for $x \neq k\pi$.

$$ \frac{d}{dx}\left(\csc x\right) = -\csc x\cot x $$

See the derivative of csc(x) step by step in the calculator →

📈 Graph of csc(x) and its derivative

Graph of csc(x) (solid) and its derivative (dashed) −π−π/20π/2π−5−4−3−2−1012345 f(x) = csc xf′(x) = −csc x · cot x
csc has U-shaped branches like sec, shifted by $\frac{\pi}{2}$. The derivative is $0$ at the turning points $x = \pm\frac{\pi}{2}$ and has asymptotes at $x = k\pi$ where $\sin x = 0$.

🔍 Why is the derivative of csc(x) equal to $-\csc x\cot x$?

$\csc x = (\sin x)^{-1}$; by the chain rule

$$ (\csc x)' = -(\sin x)^{-2}\cos x = -\frac{1}{\sin x}\cdot\frac{\cos x}{\sin x} = -\csc x\cot x. $$

🔗 Derivative of csc(x) with an inner function

If the argument is a function $u(x)$, the chain rule adds the inner derivative:

$$ \frac{d}{dx}\csc\big(u(x)\big) = -u'(x)\csc\big(u(x)\big)\cot\big(u(x)\big) $$

✏️ Worked examples

FunctionDerivativeNote
$\csc(3x)$$-3\csc(3x)\cot(3x)$ steps →
$\csc^2 x$$-2\csc^2 x\cot x$ steps →
$\frac{1}{\sin(x^2)}$$-\frac{2x\cos(x^2)}{\sin^2(x^2)}$Same rule written with sine. steps →
$x\csc x$$\csc x - x\csc x\cot x$Product rule. steps →

⚠️ Common mistakes

Writing $+\csc x\cot x$ – the minus sign belongs to every "co"-function.

Confusing $\csc x$ with $\arcsin x = \sin^{-1}x$.

❓ Frequently asked questions

What is the derivative of 1/sin(x)?

$-\frac{\cos x}{\sin^2 x} = -\csc x\cot x$.

What is the derivative of csc²(x)?

$-2\csc^2 x\cot x$.

Where is the derivative of csc(x) zero?

Where $\cos x = 0$, i.e. at $x = \frac{\pi}{2} + k\pi$.