CAS Calculator Online
Use this lightweight CAS-style calculator to evaluate expressions, estimate derivatives, and approximate roots.
Supported functions: sin, cos, tan, asin, acos, atan, sqrt, abs, ln, log, exp, pow, min, max, floor, ceil, round. Use * for multiplication and ^ for powers.
What is a CAS calculator online?
A CAS calculator online is a browser-based tool inspired by a Computer Algebra System (CAS). A full CAS can do symbolic algebra, calculus, equation solving, and expression simplification. This page provides a practical mini version for everyday work: evaluating formulas, estimating derivatives at a point, and finding approximate roots numerically.
How to use this CAS calculator
1) Evaluate an expression
Enter an expression for f(x), choose a value of x, and click Evaluate f(x). This is useful for checking homework, testing models, or validating quick calculations.
2) Estimate a derivative
Click Derivative f′(x) to compute a numerical derivative using a central-difference method. This gives the slope of the function at your selected x-value.
3) Find a root
Click Find Root to approximate a solution to f(x)=0 near your initial guess. Internally, this uses Newton-style iteration, which is fast for many smooth functions.
Examples you can try right now
- Polynomial:
x^2 + 3*x - 10 - Trigonometric:
sin(x) - 0.5 - Exponential:
exp(x) - 7 - Logarithmic:
ln(x) + x - 3(use positive x)
Why people use an online CAS tool
- No installation required
- Works on desktop, tablet, and phone
- Great for quick checks before writing full solutions
- Useful in algebra, calculus, statistics, physics, and engineering workflows
Important notes
This calculator is designed for speed and convenience. It does not replace advanced symbolic engines used in research or high-level coursework. If your expression has discontinuities, sharp corners, or a poor root guess, numerical methods may fail or return unstable values. Try changing the initial guess or simplifying your formula.
Tips for better results
- Always type explicit multiplication:
2*xinstead of2x. - Use parentheses generously:
(x+1)/(x-2). - For roots, pick an initial guess near where the graph crosses zero.
- For logs and square roots, ensure valid domains (e.g.,
x > 0forln(x)).
Final thoughts
If you need a clean, fast cas calculator online for everyday equation work, this page gives you a practical starting point. Evaluate, differentiate, and solve in seconds, then carry the results into your class notes, analysis, or project reports.