Free Online Derivative Calculator with Steps

Calculate the derivative of any function instantly. Our easy-to-use tool provides accurate results and step-by-step solutions to help you understand calculus concepts.

Enter Your Function

Welcome to the most intuitive and powerful free **derivative calculator** on the web. Type your function below to get started.

How to Use Our Step-by-Step Derivative Calculator

Our tool is designed for simplicity and power. Follow these easy steps to find the derivative of your function:

  1. Enter the Function: In the `f(x) =` input field, type the function you want to differentiate. Be sure to use standard mathematical notation. For example, use `*` for multiplication (`2*x`), `^` for exponents (`x^3`), and function names like `sin(x)`, `cos(x)`, `ln(x)`.
  2. Specify the Variable: The calculator defaults to differentiating with respect to `x`. If you are using a different variable (e.g., `t` or `y`), you can change it in the smaller input box.
  3. Calculate: Click the "Calculate Derivative" button.
  4. View Results: The tool will instantly display the simplified derivative of your function, along with a detailed step-by-step breakdown of how the solution was reached.

What is a Derivative? A Complete Guide

In calculus, the **derivative** is one of the most fundamental concepts. At its core, the derivative of a function measures the instantaneous rate of change of the function with respect to one of its variables. This might sound abstract, but it has a very clear and intuitive geometric interpretation.

The Geometric Interpretation: Slope of a Tangent Line

Imagine a smooth, curving line plotted on a graph, representing a function `f(x)`. If you pick any single point on that curve, you can draw a straight line that just "touches" the curve at that exact point without crossing through it. This line is called the **tangent line**. The derivative of the function at that specific point is simply the **slope** of this tangent line.

  • If the derivative is **positive**, the function is increasing at that point (the tangent line slopes upwards).
  • If the derivative is **negative**, the function is decreasing (the tangent line slopes downwards).
  • If the derivative is **zero**, the function has a "flat spot" — a local maximum, minimum, or an inflection point.

Because the slope of the tangent line changes as you move along the curve, the derivative is not just a single number; it's a new function itself, often denoted as `f'(x)` (read as "f prime of x") or `dy/dx`, which gives you the slope at *any* point `x`.

The Formal Definition: Limit of the Difference Quotient

Mathematically, the derivative is defined using the concept of limits. It is the limit of the average rate of change between two points on the curve as the distance between those points approaches zero. This is expressed by the formula:

f'(x) = limh→0 [f(x+h) - f(x)] / h

This formula, known as the difference quotient, is the rigorous foundation of differentiation. While it's powerful, calculating derivatives this way can be tedious. This is why a set of differentiation rules were developed, and why a reliable online **derivative calculator** can be an indispensable tool for students and professionals alike.

Common Differentiation Rules

To avoid using the limit definition every time, mathematicians have established a set of rules for finding derivatives of common functions. Our calculator applies these rules automatically. Here are some of the most essential ones:

1. The Power Rule

This is often the first rule students learn. For any function of the form `f(x) = x^n`, where `n` is any real number:

d/dx (xn) = n * xn-1

Example: The derivative of `x^3` is `3 * x^(3-1) = 3x^2`.

2. The Product Rule

Used when differentiating a function that is the product of two other functions, `f(x) = u(x) * v(x)`:

f'(x) = u'(x)v(x) + u(x)v'(x)

Example: For `x^2 * sin(x)`, the derivative is `2x*sin(x) + x^2*cos(x)`.

3. The Quotient Rule

Used for functions that are a division of two other functions, `f(x) = u(x) / v(x)`:

f'(x) = [u'(x)v(x) - u(x)v'(x)] / [v(x)]2

This is often remembered by the mnemonic "low d-high minus high d-low, square the bottom and away we go."

4. The Chain Rule

Perhaps the most powerful rule, used for composite functions (a function inside another function), like `f(g(x))`:

d/dx [f(g(x))] = f'(g(x)) * g'(x)

In essence, you differentiate the "outside" function, keeping the "inside" function the same, and then multiply by the derivative of the "inside" function.

Example: For `sin(x^3)`, the derivative is `cos(x^3) * 3x^2`.

5. Derivatives of Common Functions

  • Trigonometric: `d/dx(sin(x)) = cos(x)`, `d/dx(cos(x)) = -sin(x)`.
  • Exponential & Logarithmic: `d/dx(e^x) = e^x`, `d/dx(ln(x)) = 1/x`.

Real-World Applications of Derivatives

Derivatives are not just an academic exercise; they are the mathematical language used to describe change in countless fields.

Physics: Velocity and Acceleration

If a function `s(t)` describes the position of an object over time `t`, then its derivative, `s'(t)`, gives the object's instantaneous **velocity**. Taking the derivative again, `s''(t)`, gives its instantaneous **acceleration**.

Economics and Business: Marginal Analysis

In economics, "marginal" means the rate of change. The derivative of a cost function `C(x)` gives the **marginal cost**, the cost of producing one additional unit. Similarly, the derivative of a revenue function `R(x)` gives the **marginal revenue**.

Optimization Problems

Because derivatives can find where a function's slope is zero, they are essential for optimization. This is used to find the maximum or minimum values of a function, such as maximizing profit, minimizing material usage for a container, or finding the maximum height of a projectile.

Frequently Asked Questions

What notation should I use for functions?
Our calculator uses standard mathematical notation. Use `*` for multiplication, `^` for exponents, and parentheses `()` to group terms. For functions, use names like `sqrt()`, `sin()`, `cos()`, `tan()`, `ln()`, `log()`, and `exp()`. For example: `4*x^2 + sin(x/2)`.
Can this tool calculate higher-order derivatives?
Currently, this tool is optimized for calculating the first derivative. To find the second derivative, you can take the result from the first calculation and enter it back into the calculator. We are working on adding built-in support for higher-order derivatives.
What's the difference between f'(x) and dy/dx?
They are two different notations for the same thing: the first derivative. `f'(x)` is Lagrange's notation, which is compact and emphasizes the derivative as a function of `x`. `dy/dx` is Leibniz's notation, which is useful for showing the relationship between variables `y` and `x` and is helpful in contexts like the chain rule and integration.
Is my data and are my calculations private?
Yes. All calculations are performed directly within your browser using a client-side JavaScript library. Your functions and data are never sent to our servers, ensuring complete privacy and security.
Why should I use this online derivative calculator instead of solving by hand?
While learning to solve derivatives by hand is a crucial part of learning calculus, using an online **derivative calculator** serves several important purposes. It allows you to:
  • Check Your Work: Quickly verify your homework answers to ensure you are on the right track.
  • Save Time: For complex functions, manual differentiation can be long and prone to errors. Our tool provides instant, accurate results.
  • Learn the Steps: Our step-by-step solutions can help you understand the process and identify where you might be going wrong in your own calculations.
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