Completing the Square Formula:
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Completing the square is a method for solving quadratic equations by rewriting them in perfect square form. It's a fundamental technique in algebra that's used to derive the quadratic formula and understand the properties of quadratic functions.
The calculator uses the completing the square formula:
Where:
Explanation: The formula transforms the quadratic equation ax² + bx + c = 0 into vertex form, revealing the roots (solutions) of the equation.
Details: This method is crucial for understanding quadratic functions, finding their maximum/minimum points (vertex), and solving equations that can't be factored easily. It's also the basis for the quadratic formula.
Tips: Enter the coefficients a, b, and c from your quadratic equation in the form ax² + bx + c = 0. The calculator will provide real or complex solutions.
Q1: What if I get complex solutions?
A: Complex solutions (with 'i') occur when the discriminant is negative, meaning the parabola doesn't cross the x-axis.
Q2: Why can't coefficient a be zero?
A: If a=0, the equation becomes linear (bx + c = 0), not quadratic, and requires a different solving method.
Q3: How is this related to the quadratic formula?
A: The quadratic formula is derived by completing the square for the general quadratic equation.
Q4: When should I use completing the square vs factoring?
A: Use completing the square when the quadratic doesn't factor easily, or when you need the vertex form.
Q5: Can this method be used for graphing?
A: Yes, the completed square form directly reveals the vertex of the parabola, making it ideal for graphing.