WebCAS is a complete computer algebra system (CAS) that runs entirely in your Web browser, with no installation, no server and no account, so your computations never leave your machine.
Written from scratch in plain JavaScript, with no dependencies beyond MathJax for typesetting, it provides exact arithmetic with arbitrary-size integers, rationals, radicals and complex numbers. Its algebra covers polynomial factorization over the rationals and Gaussian rationals, partial fractions and simplification of trigonometric, logarithmic and radical expressions.
The calculus engine handles derivatives, series, limits, symbolic sums and Laplace transforms. At its core is symbolic integration built on the Risch algorithm: for a large class of integrands, including rational, exponential, logarithmic and trigonometric ones, WebCAS either finds an elementary antiderivative or proves that none exists. Beyond elementary functions, it can express antiderivatives with erf, Ei, Si, Ci, polylogarithms, Bessel and hypergeometric functions. Definite integrals are corrected for branch-cut discontinuities, and results of integration, equation solving and differential equations are checked numerically before they are shown.
WebCAS also solves equations and systems, both symbolically and numerically. It computes with matrices and eigenvalues, solves ODEs and PDEs in closed form or numerically, and takes assumptions on variables into account. It draws function, parametric, density and contour plots, which can be exported to SVG, PNG or pgfplots. All of this works in a notebook interface with a full programming language (functions, lambdas, loops), and sessions can be exported as scripts or LaTeX.
