What does evaluate mean?
Replace the variable with a number and compute the result.
Function Calculator
Plug x into f(x)=ax²+bx+c or f(x)=ax+b and read f(x).
Enter coefficients and x
Choose linear or quadratic, then evaluate at x.
About this calculator
How to use Function Calculator, plus the formulas and logic behind the results.
Tool description
Polynomial evaluation substitutes the number x into the expression and simplifies using arithmetic.
How to use
- Select quadratic or linear.
- Enter coefficients.
- Enter the evaluation point x.
- Select Calculate to view f(x).
Formulas & reference
f(x) = ax² + bx + cf(x) = ax + b
Examples
- x² − 2x + 1 at x=3 → 4
- 2x+5 at x=−1 → 3
- a=0 quadratic degenerates to linear
- Educational floating-point output
Calculation logic
Substitutes x into the selected polynomial and formats the numeric result.
For a table of many x values, use the Graphing Calculator (table mode).
Function Calculator FAQ
Common questions about this calculator and how to use the results.
Can coefficients be decimals?
Yes.
Is this graphing?
No—single-point evaluation only.
What if I need many points?
Use the graphing (table of values) calculator.
Does order of operations matter?
Yes; powers are applied before multiplication and addition.
Can x be negative?
Yes.