To write a PHP program that finds the real solutions of a quadratic equation Ax² + Bx + C = 0, we need to implement a function that calculates the discriminant, = B² - 4AC. Based on the v

<?php

/**
 * Solves a quadratic equation of the form Ax^2 + Bx + C = 0
 * and prints its real solutions.
 *
 * @param float $a The coefficient of x^2.
 * @param float $b The coefficient of x.
 * @param float $c The constant term.
 */
function solveQuadratic($a, $b, $c) {
    // Step 1: Check if 'a' is zero. If so, it's not a quadratic equation.
    if ($a == 0) {
        echo "Error: The coefficient 'a' cannot be zero for a quadratic equation.\n";
        return;
    }

    echo "For the quadratic equation " . $a . "x^2 + " . $b . "x + " . $c . " = 0:\n";

    // Step 2: Calculate the discriminant.
    $discriminant = ($b * $b) - (4 * $a * $c);

    // Step 3: Determine solutions based on the discriminant's value.
    if ($discriminant < 0) {
        echo "The discriminant (B^2 - 4AC) is " . $discriminant . ", which is negative.\n";
        echo "Therefore, there are no real solutions to the equation.\n";
    } else if ($discriminant == 0) {
        // One real solution
        $x = -$b / (2 * $a);
        echo "The discriminant (B^2 - 4AC) is " . $discriminant . ".\n";
        echo "The quadratic equation has one real solution: x = " . $x . "\n";
    } else { // $discriminant > 0
        // Two distinct real solutions
        $x1 = (-$b + sqrt($discriminant)) / (2 * $a);
        $x2 = (-$b - sqrt($discriminant)) / (2 * $a);
        echo "The discriminant (B^2 - 4AC) is " . $discriminant . ".\n";
        echo "The quadratic equation has two distinct real solutions:\n";
        echo "x1 = " . $x1 . "\n";
        echo "x2 = " . $x2 . "\n";
    }
}

// Example Usage:

// Test Case 1: Two distinct real solutions (x^2 - 5x + 6 = 0)
echo "--- Test Case 1: x^2 - 5x + 6 = 0 ---\n";
solveQuadratic(1, -5, 6);
echo "\n";

// Test Case 2: One real solution (x^2 + 4x + 4 = 0)
echo "--- Test Case 2: x^2 + 4x + 4 = 0 ---\n";
solveQuadratic(1, 4, 4);
echo "\n";

// Test Case 3: No real solutions (x^2 + x + 1 = 0)
echo "--- Test Case 3: x^2 + x + 1 = 0 ---\n";
solveQuadratic(1, 1, 1);
echo "\n";

// Test Case 4: Coefficient 'a' is zero (not a quadratic equation)
echo "--- Test Case 4: 0x^2 + 2x + 4 = 0 ---\n";
solveQuadratic(0, 2, 4);
echo "\n";

?>