Binomial Expansion of (x-y)^4
In algebra, the binomial expansion is a powerful tool for expanding expressions of the form (a+b)^n, where a and b are variables and n is a positive integer. In this article, we will explore the binomial expansion of (x-y)^4.
What is Binomial Expansion?
Binomial expansion is a method of expanding an expression of the form (a+b)^n, where a and b are variables and n is a positive integer. It is based on the principle that the expression can be expanded into a sum of terms, each term being a product of the variables a and b, raised to a power that is less than or equal to n.
Binomial Expansion of (x-y)^4
To expand (x-y)^4, we can use the binomial theorem, which states that:
(x-y)^4 = x^4 - 4x^3y + 6x^2y^2 - 4xy^3 + y^4
This expansion can be obtained by using the binomial theorem formula, which is:
(a+b)^n = a^n + na^(n-1)b + (n(n-1)/2)a^(n-2)b^2 + ... + b^n
In this case, we have a = x and b = -y, and n = 4. Plugging these values into the formula, we get:
(x-y)^4 = x^4 - 4x^3y + 6x^2y^2 - 4xy^3 + y^4
Interpretation of the Expansion
The expansion of (x-y)^4 consists of five terms:
- x^4: This term represents the product of x multiplied by itself four times.
- -4x^3y: This term represents the product of x multiplied by itself three times and y multiplied by itself once, with a negative coefficient.
- 6x^2y^2: This term represents the product of x multiplied by itself twice and y multiplied by itself twice.
- -4xy^3: This term represents the product of x multiplied by itself once and y multiplied by itself three times, with a negative coefficient.
- y^4: This term represents the product of y multiplied by itself four times.
Each term in the expansion represents a possible combination of x and y, with a coefficient that indicates the number of ways in which the combination can be formed.
Applications of Binomial Expansion
The binomial expansion of (x-y)^4 has several applications in mathematics and other fields:
- Algebraic manipulations: Binomial expansion can be used to simplify algebraic expressions and to solve equations.
- Geometry: Binomial expansion can be used to find the area and volume of geometric shapes, such as triangles and spheres.
- Calculus: Binomial expansion can be used to approximate functions and to find derivatives and integrals.
In conclusion, the binomial expansion of (x-y)^4 is a powerful tool for expanding expressions of the form (a+b)^n. It has several applications in mathematics and other fields, and it is an important concept to understand for anyone studying algebra and beyond.