Complete The Square Formula:
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Completing the square is an algebraic technique used to solve quadratic equations, convert quadratic expressions into vertex form, and derive the quadratic formula. It transforms a quadratic expression into a perfect square trinomial plus a constant.
The standard complete the square formula:
Where:
Explanation: This method rearranges the quadratic equation ax² + bx + c = 0 into a perfect square form, making it easier to solve for x.
Details: Completing the square is essential for finding the vertex of a parabola, solving quadratic equations, graphing quadratic functions, and deriving important mathematical formulas.
Tips: Enter the coefficients a, b, and c from your quadratic equation in the form ax² + bx + c = 0. Coefficient a cannot be zero.
Q1: Why complete the square instead of using the quadratic formula?
A: Completing the square helps understand the derivation of the quadratic formula and is useful for converting equations to vertex form for graphing.
Q2: What if coefficient a is not 1?
A: The formula accounts for any non-zero value of a by dividing the b term by 2a and adjusting the constant term accordingly.
Q3: Can this method be used for all quadratic equations?
A: Yes, completing the square works for all quadratic equations with real coefficients where a ≠ 0.
Q4: How is this related to the vertex form of a quadratic?
A: The completed square form directly gives the vertex coordinates: (-h, k) where (x - h)² = k.
Q5: What are the limitations of this method?
A: The main limitation is that it requires a ≠ 0 and can be computationally intensive for equations with large coefficients or decimals.