`; // Calculate discriminant const discriminant = b * b - 4 * a * c; solutionHTML += ``; // Calculate solutions based on discriminant if (discriminant > 0) { // Two real solutions const sqrtD = Math.sqrt(discriminant); const x1 = (-b + sqrtD) / (2 * a); const x2 = (-b - sqrtD) / (2 * a); solutionHTML += ` `; } else if (discriminant === 0) { // One real solution const x = -b / (2 * a); solutionHTML += ` `; } else { // Complex solutions const realPart = -b / (2 * a); const imaginaryPart = Math.sqrt(-discriminant) / (2 * a); solutionHTML += ` `; } showResult('Quadratic Equation Solution', solutionHTML); } catch (error) { showError('Error solving quadratic equation. Please check your input format.'); console.error(error); } } // Solve equation (linear) function solveEquation() { const input = document.getElementById('expression').value.trim(); if (!input) { showError('Please enter an equation to solve.'); return; } // Check if it's a quadratic equation if (input.includes('x^2') || input.includes('x²') || input.includes('x2')) { if (confirm('This appears to be a quadratic equation. Would you like to use the quadratic solver instead?')) { solveQuadratic(); return; } } // Check if it's an equation (contains =) if (!input.includes('=')) { showError('Please enter a valid equation with an equals sign (=).'); return; } const parts = input.split('='); if (parts.length !== 2) { showError('Invalid equation format. Use format: expression = expression'); return; } try { // Simple linear equation solver: ax + b = cx + d const left = parts[0].trim(); const right = parts[1].trim(); // Extract coefficients (simplified approach) let a = 0, b = 0, c = 0, d = 0; // Check for x terms and constants on both sides if (left.includes('x')) { const leftParts = left.split(/(?=[+-])/); for (let part of leftParts) { if (part.includes('x')) { const coeff = part.replace('x', '') || '1'; a += parseFloat(coeff); } else { b += parseFloat(part); } } } else { b = parseFloat(left); } if (right.includes('x')) { const rightParts = right.split(/(?=[+-])/); for (let part of rightParts) { if (part.includes('x')) { const coeff = part.replace('x', '') || '1'; c += parseFloat(coeff); } else { d += parseFloat(part); } } } else { d = parseFloat(right); } // Solve: ax + b = cx + d => (a-c)x = d-b => x = (d-b)/(a-c) const coefficient = a - c; const constant = d - b; let solutionHTML = ''; solutionHTML += ``; solutionHTML += ``; solutionHTML += ``; solutionHTML += ``; if (coefficient === 0) { if (constant === 0) { solutionHTML += ``; } else { solutionHTML += ``; } } else { const solution = constant / coefficient; solutionHTML += ``; } showResult('Equation Solution', solutionHTML); } catch (error) { showError('Error solving equation. Please check your input format.'); console.error(error); } } // Simplify expression function simplifyExpression() { const input = document.getElementById('expression').value.trim(); if (!input) { showError('Please enter an expression to simplify.'); return; } try { let simplified = input; // Remove spaces simplified = simplified.replace(/\s/g, ''); let resultHTML = ``; // Combine like terms (basic implementation) if (simplified.includes('+') || simplified.includes('-')) { const terms = simplified.split(/(?=[+-])/); let xCoefficient = 0; let constant = 0; for (let term of terms) { if (term.includes('x')) { const coeff = term.replace('x', '') || (term.startsWith('-') ? '-1' : '1'); xCoefficient += parseFloat(coeff); } else { constant += parseFloat(term); } } // Build simplified expression let result = ''; if (xCoefficient !== 0) { result += (xCoefficient === 1 ? '' : (xCoefficient === -1 ? '-' : xCoefficient)) + 'x'; } if (constant !== 0) { if (result && constant > 0) result += ' + '; if (constant < 0) result += ' - '; result += Math.abs(constant); } if (!result) result = '0'; resultHTML += ``; resultHTML += ``; resultHTML += ``; showResult('Simplified Expression', resultHTML); } else { showResult('Simplified Expression', `${resultHTML}`); } } catch (error) { showError('Error simplifying expression. Please check your input format.'); console.error(error); } } // Evaluate expression function evaluateExpression() { const input = document.getElementById('expression').value.trim(); if (!input) { showError('Please enter an expression to evaluate.'); return; } try { const parsedExpr = parseExpression(input); // For safety, we'll only evaluate simple arithmetic expressions if (/[a-zA-Z]/.test(parsedExpr)) { showError('Evaluation with variables is not supported. Try using numbers only or use "Simplify" for expressions with variables.'); return; } const result = eval(parsedExpr); const resultHTML = ` `; showResult('Evaluation Result', resultHTML); } catch (error) { showError('Error evaluating expression. Please check your input format.'); console.error(error); } } // Expand expression function expandExpression() { const input = document.getElementById('expression').value.trim(); if (!input) { showError('Please enter an expression to expand.'); return; } try { let expanded = input; let steps = []; steps.push(``); // Expand a(b+c) to ab + ac const expandPattern = /(\d*[a-zA-Z]?)\(([^()]+)\)/; let match; while ((match = expanded.match(expandPattern))) { const [full, factor, inner] = match; const terms = inner.split(/(?=[+-])/); let result = ''; for (let i = 0; i < terms.length; i++) { const term = terms[i]; if (term) { if (i > 0 && !term.startsWith('-') && !term.startsWith('+')) { result += '+'; } if (factor && factor !== '1') { if (factor === '-') { result += '-' + term; } else { result += factor + '*' + term; } } else { result += term; } } } steps.push(``); expanded = expanded.replace(full, result); } steps.push(``); showResult('Expanded Expression', steps.join('')); } catch (error) { showError('Error expanding expression. Please check your input format.'); console.error(error); } } // Factor expression function factorExpression() { const input = document.getElementById('expression').value.trim(); if (!input) { showError('Please enter an expression to factor.'); return; } try { let factored = input; let resultHTML = ``; // Simple factoring for quadratic expressions: ax² + bx + c if (input.includes('x^2') || input.includes('x²') || input.includes('x2')) { const coefficients = extractQuadraticCoefficients(input + '=0'); if (coefficients) { const { a, b, c } = coefficients; resultHTML += ``; // Try to factor const factors = factorQuadratic(a, b, c); if (factors) { resultHTML += ``; } else { resultHTML += ``; } } } else { factored = 'This calculator can only factor quadratic expressions.'; resultHTML += ``; } showResult('Factored Expression', resultHTML); } catch (error) { showError('Error factoring expression. Please check your input format.'); console.error(error); } } // Helper function to factor quadratic expressions function factorQuadratic(a, b, c) { // For simple cases where a=1 if (a === 1) { // Find two numbers that multiply to c and add to b for (let i = -Math.abs(c); i <= Math.abs(c); i++) { if (i !== 0 && c % i === 0) { const j = c / i; if (i + j === b) { return `(x + ${i})(x + ${j})`; } } } } // For difference of squares if (b === 0 && c < 0) { const sqrt = Math.sqrt(-c); if (Number.isInteger(sqrt)) { return `(x + ${sqrt}i)(x - ${sqrt}i)`; } } return null; } // Add keyboard support document.getElementById('expression').addEventListener('keypress', function(e) { if (e.key === 'Enter') { solveEquation(); } });