# Math Solver

> Step-by-step math solutions with an independent, in-browser check of the final answer.
> https://math-solver.skillsafe.ai/

Type or paste one math problem - arithmetic, algebra, equations, inequalities, systems,
trigonometry, exponents and logarithms, limits, derivatives, integrals, or a word problem - and
get numbered steps (each naming the rule it uses), a final answer, and a numeric check of that
answer that runs in the browser.

## What is free

- A live preview of how the typed math was read, rendered as math notation.
- Numeric answers computed in the browser before any run: real roots of a one-variable equation
  in [-100, 100], the value of a closed expression, a definite integral, a limit estimate.
- Ten saved worked examples, including one deliberately wrong answer that the check catches.

## What is paid

- Solving a new problem, and explaining one step in more depth, are metered runs on SkillSafe
  credits (model alias gpt-terra). No API key is needed: sign in and pay per run. The price shown
  before a run is a hold; the charge is what the run used.

## The answer check

The solver restates its final answer in plain calculator syntax. The page then substitutes
numbers: each solution back into every equation, a root scan for solutions the answer missed
(including periodic families), a numeric derivative, a numeric antiderivative check, adaptive
Simpson quadrature for definite integrals, one-sided limits, random-point identity tests for
simplification, and sample-point tests for inequality solution sets. Verdicts: verified, check
failed, inconclusive, not checkable. For word problems it checks the algebra, not the set-up.

## API

- Docs: https://math-solver.skillsafe.ai/api.html
- Base: https://api.skillsafe.ai/v1/app-api (endpoints /me, /estimate, /run, /run-stream)
- Input: {"task": "solve" | "explain", "problem": "...", "level": "auto" | "school" | "university",
  "facts": "<JSON string>", "steps": "<JSON string>", "step": 2, "question": "..."}
- Output: one JSON object; for solve it carries steps[], final_answer {latex, text} and check
  {type, ...}; for explain it carries headline, explanation, sub_steps[], key_idea, watch_out.

## Credits

Math typesetting by KaTeX (MIT). Built on SkillSafe.