(x+y)^4 Binomial Expansion

4 min read Jun 17, 2024

Understanding Binomial Expansion: (x + y)⁴

The binomial theorem is a powerful tool in algebra that allows us to expand expressions of the form (x + y)ⁿ, where n is a non-negative integer. This article will focus on the specific case of (x + y)⁴, exploring the expansion and its applications.

The Binomial Theorem:

The binomial theorem states that:

(x + y)ⁿ = ∑_(k=0)^n (n choose k) * x^(n-k) * y^k

Where:

(n choose k) represents the binomial coefficient, calculated as n! / (k! * (n-k)!). It signifies the number of ways to choose k objects from a set of n objects.
∑_(k=0)^n indicates the sum from k = 0 to k = n.

Expanding (x + y)⁴:

Using the binomial theorem, let's expand (x + y)⁴ step by step:

(x + y)⁴ = (4 choose 0) * x⁴ * y⁰ + (4 choose 1) * x³ * y¹ + (4 choose 2) * x² * y² + (4 choose 3) * x¹ * y³ + (4 choose 4) * x⁰ * y⁴

Calculating the binomial coefficients:

(4 choose 0) = 1
(4 choose 1) = 4
(4 choose 2) = 6
(4 choose 3) = 4
(4 choose 4) = 1

Substituting the values:

(x + y)⁴ = 1 * x⁴ * 1 + 4 * x³ * y + 6 * x² * y² + 4 * x * y³ + 1 * 1 * y⁴

Therefore, the final expanded form is:

(x + y)⁴ = x⁴ + 4x³y + 6x²y² + 4xy³ + y⁴

Applications of Binomial Expansion:

Binomial expansion has a wide range of applications in mathematics, physics, and other fields. Here are a few examples:

Finding Probabilities: Binomial expansion can be used to calculate probabilities in situations involving multiple trials with two possible outcomes, such as coin flips or dice rolls.
Approximating Functions: For large values of n, the binomial theorem provides a way to approximate functions like (1 + x)ⁿ. This is especially useful in calculus and statistics.
Solving Algebraic Equations: Binomial expansion can be used to simplify complex algebraic expressions and solve equations.

Conclusion:

Understanding binomial expansion is a crucial skill in mathematics. This article has demonstrated the expansion of (x + y)⁴ and highlighted the various applications of this fundamental concept. By mastering the binomial theorem, you gain a powerful tool for solving problems in diverse fields.