Understanding the (x + a)² Formula
The formula (x + a)² is a fundamental concept in algebra, frequently used for simplifying expressions and solving equations. It represents the square of a binomial, which is an expression with two terms.
Expanding the Formula
To understand the formula, let's expand it:
(x + a)² = (x + a)(x + a)
Applying the distributive property (or FOIL method), we get:
(x + a)² = x(x + a) + a(x + a) (x + a)² = x² + xa + ax + a² (x + a)² = x² + 2ax + a²
Key Points
- The formula is derived from the expansion of the binomial (x + a).
- It is crucial to remember that the middle term in the expansion is twice the product of x and a.
- The last term is the square of a.
Applications of the Formula
This formula has numerous applications in various fields, including:
- Algebraic Simplification: It simplifies expressions involving squares of binomials, making them easier to manipulate.
- Solving Equations: The formula can be applied to solve quadratic equations by factoring or completing the square.
- Geometry: It plays a role in deriving formulas for areas and volumes of geometric shapes.
- Calculus: The formula is used to differentiate and integrate expressions involving squares of binomials.
Examples
Let's illustrate with some examples:
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Simplify (2x + 3)²: Applying the formula, we get: (2x + 3)² = (2x)² + 2(2x)(3) + (3)² (2x + 3)² = 4x² + 12x + 9
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Solve the equation (x + 5)² = 16: Taking the square root of both sides, we get: x + 5 = ±4 Solving for x, we get: x = -1 or x = -9
Conclusion
The (x + a)² formula is a fundamental concept in mathematics, offering a powerful tool for simplifying expressions and solving equations. Its applications extend beyond algebra to various fields, emphasizing its importance in mathematical understanding.