Composite Function Calculator: Simplify Your Math

This tool helps you easily compute the result of composite functions by combining two functions step-by-step.

How to Use the Composite Function Calculator

This calculator allows you to calculate the composite function f(g(x)).


  1. Enter the mathematical expression for the function f(x) in the “Function f(x)” field, for example, 2*x+3.
  2. Enter the mathematical expression for the function g(x) in the “Function g(x)” field, for example, x^2.
  3. Enter the value for x in the “Value of x” field, for example, 5.
  4. Press the “Calculate” button to get the composite function result f(g(x)).

How It Works

The script takes the input functions f(x) and g(x) as well as the value of x. It then evaluates g(x) using the input value x, and subsequently evaluates f(g(x)) to produce the final result.

The functions are converted to JavaScript functions using the Function constructor, which allows for dynamic evaluation of the function expressions using the input value.


There are several limitations to this calculator:

  • The input functions must be valid JavaScript expressions. For example, use Math.pow(x, 2) for x squared instead of x^2.
  • Complex mathematical functions that are not standard JavaScript functions will not be evaluated correctly.
  • Ensure your function syntax is correct, otherwise, an error message will be displayed.

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