GraphCalc 84: Graphing Calc

iOS Universel / Education

A full graphing calculator with the layout and feel of a classic handheld — built for iPhone and iPad. Plot up to 9 equations, run TI-style programs, solve systems, fit regressions. No ads, no subscriptions, no internet required.

GraphCalc 84 is the classic graphing calculator, rebuilt for your phone — complete, faithful, and fast. If you know the TI-84, your muscle memory works on day one.

Graph everything. Function, parametric, polar, and sequence modes with nine equation slots, trace, tables (Auto or Ask), zoom — including ZoomStat — and full window control. Find zeros, minima, maxima, intersections, derivatives, and integrals right from the CALC menu.

Statistics, complete. Every hypothesis test and confidence interval — Z, T, 2-sample, proportions, χ², χ²-GOF, F, LinRegTTest, ANOVA — plus 1-Var/2-Var Stats and 13 regression models with TI-accurate quartiles. Visualize with scatter, xyLine, histograms, box-and-whisker, and normal probability plots, and shade distribution areas right on the graph.

Real fractions with ►Frac/►Dec and mixed-number display. Number bases from binary to hex with bitwise operators.

Your AI tutor (new in 1.7). Long-press any answer — or any error — for a clear step-by-step explanation. Ask for worked steps when a problem is beyond the built-in solver. Have your graphs described in plain language, from intercepts to asymptotes, computed by the calculator and narrated by AI. All AI features are optional: bring your own Anthropic API key, keep it securely on your device, and send nothing until you choose to. Without a key, GraphCalc 84 remains complete and fully offline.

Exact where you want it (new in 2.0). Switch ANSWERS mode to Auto and results stay mathematically exact — fractions, simplified radicals, multiples of π — with ►Dec one press away. Four symbolic commands bring real algebra: simplify, expand, factor with exact roots, and derivatives. Prefer decimals? Everything stays exactly as it was until you opt in.

Programmable. Write and run TI-BASIC programs — control flow, input/output, and the complete DRAW command set, down to reading pixels with pxl-Test(.

Beyond the original. A physical-units engine with dimensional analysis. Math Snap: point your camera at a problem, or write it by hand. A hub of 22 built-in apps — solvers, periodic table, physics constants, curve fitting, date math, and more. Twelve accessibility-tested themes, with a free web editor to design your own.

GRAPHING
• Function, parametric, polar, and sequence modes
• 9 simultaneous equations, color-coded
• ZOOM (in/out, decimal, square, standard, trig, fit), TRACE with touch-jump
• CALC: zeros, min/max, intersect, dy/dx, ∫f(x)dx
• Spiffy Graph mode — neon glow with adjustable intensity

MATH
• Trigonometry, logarithms, complex numbers (rectangular & polar)
• Matrices [A]–[J] with full linear-algebra ops
• Statistics: 1-Var, 2-Var, ten regression types including SinReg
• Distributions: Normal, t, χ², F, Binomial, Poisson, Geometric
• Probability: nPr, nCr, factorial, randInt, randNorm, randBin

APPS
• TVM Solver, Loan Calculator, Tip Split
• Equation Solver, Quadratic, Polynomial Roots, Systems
• Numerical derivative, definite integral, Riemann Explorer
• Periodic Table, Physics Constants, Coordinate / Unit Converter
• Curve Fitting, Combinatorics, Dice Probability
• Date Calculator, Vector Calculator, Step-by-Step Solver, Graph Inequalities

PROGRAMMING
• BASIC-style language with If/Then/Else, While, For, Repeat
• Draw, Line, Circle, Shade, Text, StorePic / RecallPic
• Programs persist across launches

PERSONAL
• 12 themes including amber phosphor, green phosphor, midnight, paper, porcelain, sunset — all WCAG-AA contrast certified
• External display support on iPad
• Hardware keyboard support
• Imports custom .gctheme.json files

WHY GRAPHCALC 84
• Buy once. Free updates. No ads. No subscriptions.
• Every calculation runs on-device. No account, no telemetry.

Quoi de neuf dans la dernière version ?

What's New in 2.0 — Exact answers

The biggest engine upgrade in GraphCalc 84's history: your calculator can now do math the way your textbook does.

Exact mode. Flip MODE → ANSWERS to Auto and answers stay exact: 1/3 + 1/6 is 1/2, not 0.4999999. √(8) simplifies to 2√(2). π stays π — so 2π/3 displays as 2π/3, ready for the unit circle. Prefer decimals? Leave ANSWERS on Approximate and nothing changes; or press ►Dec on any exact answer to see its decimal.

Real algebra. Four new MATH commands work symbolically:

simplify( and expand( — combine like terms, multiply out products: (X+1)² becomes X² + 2X + 1.
factor( — with exact roots, including irrational ones: X² − 2 factors into (X − √(2))(X + √(2)). Cubics and beyond factor through rational roots.
d( — the derivative, exactly: d(X³ − 2X² + X − 7) is 3X² − 4X + 1.
Results come back as expressions you can copy, re-enter, and build on.

Built on bedrock. Every exact computation is verified digit-for-digit — anything the exact engine can't represent perfectly falls back to your familiar decimal answer rather than pretending. No wrong answers, no surprises.

From real statistics to a finished machine, an AI tutor, and now exact math — thank you for making GraphCalc 84 part of how you learn.