Derivative of cosh(x)
The derivative of the hyperbolic cosine is the hyperbolic sine: $\dfrac{d}{dx}\cosh x = \sinh x$. Note the difference to the ordinary cosine, whose derivative is $-\sin x$.
See the derivative of cosh(x) step by step in the calculator →
📈 Graph of cosh(x) and its derivative
🔍 Why is the derivative of cosh(x) equal to $\sinh x$?
With $\cosh x = \frac{e^x + e^{-x}}{2}$:
The minus sign that appears in $(\cos x)'$ has no counterpart here: it comes from $i^2 = -1$ in $\cos x = \frac{e^{ix}+e^{-ix}}{2}$, and there is no $i$ in the hyperbolic case.
🔗 Derivative of cosh(x) with an inner function
If the argument is a function $u(x)$, the chain rule adds the inner derivative:
✏️ Worked examples
⚠️ Common mistakes
Writing $-\sinh x$ by analogy with $\cos x$.
Forgetting the inner derivative: $(\cosh 5x)' = 5\sinh 5x$.
❓ Frequently asked questions
Why is the derivative of cosh(x) positive sinh(x)?
Differentiating $e^{-x}$ gives $-e^{-x}$, which turns the sum $e^x + e^{-x}$ into the difference $e^x - e^{-x}$ – that is $2\sinh x$, with no extra sign.
What is the second derivative of cosh(x)?
$\cosh x$ itself.
Where does cosh(x) have its minimum?
At $x = 0$, where the derivative $\sinh x$ is zero; the minimum value is $\cosh 0 = 1$.