TI-89 Titanium Calculator Emulator
body {
font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
background-color: #f8f9fa;
color: #333;
line-height: 1.6;
margin: 0;
padding: 20px;
}
.calculator-container {
max-width: 700px;
margin: 30px auto;
background-color: #ffffff;
border-radius: 8px;
box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
padding: 30px;
overflow: hidden;
}
h1, h2 {
color: #004a99;
text-align: center;
margin-bottom: 20px;
}
.input-section, .output-section {
margin-bottom: 30px;
padding: 20px;
border: 1px solid #e0e0e0;
border-radius: 5px;
background-color: #fdfdfd;
}
.input-group {
margin-bottom: 15px;
display: flex;
align-items: center;
}
.input-group label {
flex: 1;
min-width: 150px;
margin-right: 15px;
font-weight: 500;
color: #004a99;
}
.input-group input[type="text"],
.input-group input[type="number"] {
flex: 2;
padding: 10px;
border: 1px solid #ccc;
border-radius: 4px;
font-size: 1rem;
box-sizing: border-box; /* Ensures padding doesn't affect width */
}
.input-group input:focus {
border-color: #004a99;
outline: none;
box-shadow: 0 0 0 2px rgba(0, 74, 153, 0.2);
}
button {
display: block;
width: 100%;
padding: 12px 20px;
background-color: #004a99;
color: white;
border: none;
border-radius: 5px;
font-size: 1.1rem;
cursor: pointer;
transition: background-color 0.3s ease;
margin-top: 10px;
}
button:hover {
background-color: #003366;
}
#result {
background-color: #e9ecef;
border: 1px solid #dee2e6;
padding: 15px;
text-align: center;
font-size: 1.8rem;
font-weight: bold;
color: #004a99;
margin-top: 20px;
border-radius: 5px;
}
#result-label {
display: block;
font-size: 1.2rem;
font-weight: normal;
color: #555;
margin-bottom: 10px;
}
.explanation {
margin-top: 40px;
border-top: 1px solid #e0e0e0;
padding-top: 30px;
}
.explanation h2 {
text-align: left;
margin-bottom: 15px;
}
.explanation p, .explanation ul {
margin-bottom: 15px;
}
.explanation code {
background-color: #e9ecef;
padding: 2px 5px;
border-radius: 3px;
font-family: Consolas, Monaco, 'Andale Mono', 'Ubuntu Mono', monospace;
}
@media (max-width: 600px) {
.input-group {
flex-direction: column;
align-items: stretch;
}
.input-group label {
margin-right: 0;
margin-bottom: 8px;
text-align: left;
}
.input-group input[type="text"],
.input-group input[type="number"] {
width: 100%;
}
.calculator-container {
padding: 20px;
}
h1 {
font-size: 1.8rem;
}
}
TI-89 Titanium Calculator Emulator
Simulate basic operations and expressions on the TI-89 Titanium.
Result
—
Calculated Value
Understanding the TI-89 Titanium and Expression Evaluation
The Texas Instruments TI-89 Titanium is a powerful graphing calculator renowned for its advanced features, including symbolic mathematics capabilities (Computer Algebra System – CAS). Unlike basic calculators that only perform numerical computations, the TI-89 Titanium can manipulate and simplify algebraic expressions, solve equations symbolically, and perform calculus operations.
This emulator provides a simplified interface to evaluate mathematical expressions entered in a format similar to what you would input on the actual device. The core behind this functionality is a JavaScript math expression parser and evaluator. When you enter an expression, it's parsed, and standard mathematical functions and constants are recognized.
Key Features of the TI-89 Titanium Emulated Here:
- Numerical Evaluation: Computes the numerical result of entered expressions.
- Standard Functions: Supports common mathematical functions like
sin(), cos(), tan(), sqrt(), log(), ln(), exp(), etc.
- Constants: Recognizes mathematical constants such as
pi (π) and e.
- Order of Operations: Adheres to the standard order of operations (PEMDAS/BODMAS).
- Basic Arithmetic: Handles addition (+), subtraction (-), multiplication (*), division (/), and exponentiation (^).
How the Calculation Works (Behind the Scenes):
The calculation relies on JavaScript's built-in Math object and potentially a robust expression parsing library (though for this example, a simplified approach is used). When you click "Calculate":
- The input expression string is retrieved.
- It's processed to replace common mathematical constants (like 'pi') with their numerical equivalents.
- A JavaScript `eval()` function (used cautiously here for demonstration) or a dedicated parser evaluates the expression, respecting function calls and operator precedence.
- The resulting numerical value is displayed.
Example Usage:
Let's consider evaluating 2 * sin(pi / 4) + sqrt(16).
- Input:
2 * sin(pi / 4) + sqrt(16)
- Evaluation Steps:
pi / 4 is evaluated (approx. 0.7854).sin(pi / 4) is calculated (approx. 0.7071).2 * 0.7071 is computed (approx. 1.4142).sqrt(16) is calculated (4).- Finally,
1.4142 + 4 is summed, resulting in approximately 5.4142.
- Result:
5.41421356...
This demonstrates how the calculator interprets standard mathematical notation and functions to produce a precise numerical output, mimicking a core function of the TI-89 Titanium. For complex symbolic manipulation, a full CAS implementation is required, which is beyond the scope of this basic numerical emulator.
function evaluateExpression() {
var expressionInput = document.getElementById("expression");
var resultDiv = document.getElementById("result");
var expression = expressionInput.value.trim();
if (expression === "") {
resultDiv.textContent = "Error: No input";
return;
}
// Replace common TI-89 constants and functions with JS equivalents
expression = expression.replace(/pi/gi, Math.PI.toString());
expression = expression.replace(/e/gi, Math.E.toString());
expression = expression.replace(/sqrt/gi, 'Math.sqrt');
expression = expression.replace(/sin/gi, 'Math.sin');
expression = expression.replace(/cos/gi, 'Math.cos');
expression = expression.replace(/tan/gi, 'Math.tan');
expression = expression.replace(/log/gi, 'Math.log10'); // TI-89 log is base 10
expression = expression.replace(/ln/gi, 'Math.log'); // TI-89 ln is natural log
expression = expression.replace(/exp/gi, 'Math.exp');
// Simple validation: check for invalid characters (basic)
// A more robust solution would use a proper parser
var validChars = /[0-9+\-*/^().,\s]/; // Added comma for potential use like in 1,000, but eval won't handle it well directly
var containsInvalidChars = false;
for (var i = 0; i < expression.length; i++) {
var char = expression[i];
// Allow basic math operators, numbers, parentheses, decimals, pi, e, and function names
if (!validChars.test(char) &&
!expression.substring(i).match(/^(sin|cos|tan|sqrt|log|ln|exp)/)) {
containsInvalidChars = true;
break;
}
}
if (containsInvalidChars) {
resultDiv.textContent = "Error: Invalid characters";
return;
}
try {
// WARNING: Using eval() can be a security risk if the input is not
// carefully sanitized. For this specific, controlled calculator context,
// it's used for demonstration. A production environment should use
// a dedicated math expression parser library.
// Replace commas used as decimal separators if present (e.g., "1,23")
// This is a simplification; real TI-89 behavior might differ based on settings
expression = expression.replace(/,/g, '.');
// Ensure powers are handled correctly (e.g., x^2)
// JavaScript's Math.pow expects two arguments
expression = expression.replace(/\^/g, 'Math.pow');
var result = eval(expression);
// Check if the result is a valid number
if (typeof result === 'number' && !isNaN(result) && isFinite(result)) {
// Format the output to a reasonable precision
resultDiv.textContent = result.toFixed(10); // Adjust precision as needed
} else {
resultDiv.textContent = "Error: Calculation failed";
}
} catch (error) {
console.error("Evaluation Error:", error);
resultDiv.textContent = "Error: Invalid Expression";
}
}
// Allow pressing Enter to trigger calculation
document.getElementById("expression").addEventListener("keypress", function(event) {
if (event.key === "Enter") {
event.preventDefault(); // Prevent default form submission if it were in a form
evaluateExpression();
}
});