Function Evaluator Form
Supported Input Examples
You can evaluate many common mathematical forms with this tool.
x^2 + 2*x + 1sin(x) + cos(x)sqrt(x+4)log(x)for base-10 logarithmln(x)for natural logarithma*x^2 + b*x + cexp(x/3)max(x, 3) + min(a, b)
Example Data Table
Sample expression: f(x) = x^2 + 2*x + 1
| x | f(x) |
|---|---|
| -2 | 1 |
| -1 | 0 |
| 0 | 1 |
| 1 | 4 |
| 2 | 9 |
| 3 | 16 |
Formula Used
The calculator substitutes the selected numeric values into your function and computes the resulting output. The general evaluation rule is:
y = f(x)
For parameterized expressions, the calculator evaluates:
y = f(x, a, b, c)
In range mode, it repeats the same evaluation for every x value between the chosen start and end values using the selected step size.
For advanced insight in single mode, the tool also estimates the derivative numerically with a centered difference:
f'(x) ≈ [f(x+h) - f(x-h)] / (2h)
This derivative estimate helps show the local rate of change near the chosen point.
How to Use This Calculator
- Enter a valid function using x, and optionally a, b, or c.
- Select single value mode for one output or range mode for tables.
- Choose radians or degrees when using trigonometric functions.
- Enter the x value or the range start, end, and step.
- Set parameter values if your function includes a, b, or c.
- Choose the number of decimals you want displayed.
- Press Evaluate Function to see the result above the form.
- Use the CSV or PDF buttons to export the output.
Frequently Asked Questions
1) What does this function evaluator calculate?
It computes the numeric value of a mathematical expression for chosen inputs. It also builds range tables and estimates a local derivative in single value mode.
2) Which functions are supported?
You can use sin, cos, tan, asin, acos, atan, sqrt, abs, exp, ln, log, floor, ceil, round, min, max, and pow, plus constants pi and e.
3) Does the calculator support degrees?
Yes. Choose degrees if your trigonometric input values are angles measured in degrees. Otherwise, keep the calculator in radians mode.
4) Why must I type explicit multiplication?
The parser expects forms like 2*x instead of 2x. Explicit multiplication avoids ambiguity and improves expression reliability during evaluation.
5) What happens if my function is undefined?
The calculator shows an error when the expression produces an invalid result, such as division by zero, a negative square root, or a nonpositive logarithm input.
6) What is the derivative estimate used for?
It approximates how fast the function changes near the selected x value. This is useful for checking slope behavior without doing symbolic differentiation.
7) Can I create a table of values?
Yes. Switch to range mode, enter the start, end, and step values, and the calculator will generate a structured x and f(x) table.
8) Can I export the result?
Yes. After evaluation, use the CSV button for spreadsheet-friendly output or the PDF button for a clean portable report.