# Calculadora gráfica

> Trace várias funções, curvas polares e paramétricas; mova e amplie o gráfico; encontre raízes, interseções, extremos e áreas.

Versão interativa: https://www.calcopenly.com/pt/math/graphing-calculator
Tema: Calculadoras de matemática

Plot up to six functions of x on one set of axes, alongside polar curves such as r = 1 + cos(θ) and parametric curves such as (cos(t), sin(2t)). Drag to pan, scroll or pinch to zoom, and hover to read each function's value, which is recomputed in 50-digit decimal at the pointer.

Below the plot, the calculator lists the roots, turning points and intersections visible in the current window, found by bisection on sign changes. It can also plot the derivative of the first function and shade the area under it between two limits, reporting the integral by Simpson's rule.

Trigonometric functions take radians here, as in most graphing software; type pi/2 rather than 90.

## Dados

- **f(x)**
- **x**

## Resultados

- f(x) — resultado principal

## Exemplos resolvidos

### Cubic at 2

- f(x): x^3 - 3x
- x: 2
- **f(x): 2**
- Fonte de verificação: 8 − 6

### Sine at π/2

- f(x): sin(x)
- x: pi/2
- **f(x): 1**
- Fonte de verificação: sin(π/2) = 1; the plotter works in radians

### Rational function

- f(x): 1/(x-1)
- x: 3
- **f(x): 0.5**
- Fonte de verificação: 1/2

## Perguntas

### How do I find where two graphs intersect?

Enter both functions and look at the 'Points of interest' table under the plot. It reports numerical candidates in the visible window, with coordinates rounded to 8 significant figures; this display precision does not guarantee that accuracy. Sampling can miss tangencies or closely spaced intersections. Zoom or pan to inspect the region, and check important solutions in the original equations.

### Can it plot polar and parametric equations?

Yes. Start a line with r = to plot a polar curve in θ (for example r = 2 sin(3θ) draws a three-petal rose), or write a pair in brackets such as (cos(t), sin(t)) for a parametric curve, traced for t from −2π to 2π.

### Why does tan(x) have gaps?

tan(x) has vertical asymptotes at x = π/2 + kπ, where it jumps from +∞ to −∞. The plotter breaks the line wherever consecutive samples jump by more than one and a half screen heights, so it doesn't draw false vertical lines across the asymptotes.

### Qual é a precisão de “Calculadora gráfica”?

A precisão depende dos dados inseridos e das hipóteses do método. O cálculo decimal usa 50 algarismos significativos, mas estimativas, métodos numéricos e dados de origem podem ter menor precisão; o arredondamento exibido não elimina essas limitações. Exemplos resolvidos verificados com fontes independentes: 3. Por exemplo, “Cubic at 2” é verificado com 8 − 6.

### De onde vem o método?

OpenStax Precalculus 2e — Functions, function notation and graphs; Implementation: adaptive sampling with discontinuity breaks; values at a point recomputed in 50-digit Decimal.

## Fontes

- [OpenStax Precalculus 2e — Functions, function notation and graphs](https://openstax.org/books/precalculus-2e/pages/1-1-functions-and-function-notation)
- Implementation: adaptive sampling with discontinuity breaks; values at a point recomputed in 50-digit Decimal