How SolveStep solves your math
No mystery black box. Here is exactly what happens between typing your problem and seeing the answer.
SolveStep reads what you typed (numbers, the variable x, operators and parentheses) and builds it into a structured expression tree, the same way a spreadsheet interprets a formula.
If your input contains an "=" sign, it's treated as an equation and solved algebraically. An inequality sign (< > ≤ ≥) routes to the inequality solver instead. Calculus phrasing like "d/dx" triggers the power-rule engine. Everything else is evaluated as an arithmetic expression, sin, cos, tan, log and ln included, with order of operations respected throughout.
Rather than jumping straight to a final value, the solver works through the same sequence a person would: reduce parentheses, combine like terms, isolate the variable, or apply the power rule. Each move is logged with a plain-English description of what it did. Where the result can be double-checked, as with a solved equation or a factorable quadratic, SolveStep substitutes the answer back in and shows that check as its own step.
The whole engine is JavaScript that runs locally on your device. Nothing is uploaded to a server, so results appear instantly and your problems stay private.
What SolveStep is, and what it is not
SolveStep exactly computes fraction arithmetic (no rounding drift), solves linear and quadratic equations and linear inequalities in one variable, factors quadratics with rational roots, evaluates sin/cos/tan/log/ln numerically, and applies the power rule to polynomial derivatives and integrals of any degree. It is built to be a transparent study aid rather than a substitute for understanding the method. The goal is for you to see that method clearly enough to reproduce it yourself.
It currently does not support systems of equations, calculus of trigonometric or logarithmic functions (chain rule, etc.), or multivariable calculus. If a problem falls outside that range, the tool will say so rather than guess.