Chapter 10: Problem 41
Multiply the polynomials. $$(x+y)^{2}$$
Short Answer
Expert verified
\((x+y)^{2} = x^{2} + 2xy + y^{2} \).
Step by step solution
01
- Write the polynomial in expanded form
To start, recognize that \((x+y)^{2}\) is a polynomial squared. This can be written as \((x+y) \times (x+y)\).
02
- Distribute each term
Next, distribute each term in the first polynomial to every term in the second polynomial as follows:\[ (x+y) \times (x+y) = x \times x + x \times y + y \times x + y \times y \]
03
- Simplify the multiplication
Then, perform the multiplication for each term: \[ x \times x + x \times y + y \times x + y \times y = x^{2} + xy + yx + y^{2} \]
04
- Combine like terms
Finally, combine the like terms \((xy \text{ and } yx)\):\[ x^{2} + xy + yx + y^{2} = x^{2} + 2xy + y^{2} \]
Unlock Step-by-Step Solutions & Ace Your Exams!
-
Full Textbook Solutions
Get detailed explanations and key concepts
-
Unlimited Al creation
Al flashcards, explanations, exams and more...
-
Ads-free access
To over 500 millions flashcards
-
Money-back guarantee
We refund you if you fail your exam.
Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!
Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Polynomial Expansion
When we talk about polynomial expansion, it means expressing a polynomial that needs to be multiplied out in its extended form. For example, \((x+y)^{2}\) can be expanded to \((x+y) \times (x+y)\). This step reveals all the products that need to be computed. Expanding helps to see each term that will be multiplied. It’s like unwrapping a package to see what’s inside. This makes it easier to manage the multiplication process. Once expanded, the polynomial can be simplified step by step.
Distributive Property
The distributive property is a crucial rule in algebra. It allows us to break down expressions like \((x+y) \times (x+y)\). The idea is to distribute each term in one polynomial to every term in the other polynomial. Here’s how it works:
- First, take the \(x\) from \(x+y\) and multiply it by both terms in the second \(x+y\).
- Then, take the \(y\) in \(x+y\) and multiply it by both terms in the other \(x+y\).
Combining Like Terms
Combining like terms means adding or subtracting terms that have the same variable raised to the same power. In our example \(x^{2} + xy + yx + y^{2}\):
- \(xy\) and \(yx\) are like terms because they both have the same variable parts.
Binomial Theorem
The binomial theorem provides a formula for expanding any power of a binomial without expanding step-by-step. It states that: \[
(a + b)^n = \sum_{k=0}^{n} \binom{n}{k} a^{n-k} b^k
\] For \((x+y)^{2}\), it looks like this: \[ (x+y)^{2} = \binom{2}{0}x^{2}y^{0} + \binom{2}{1}x^{1}y^{1} + \binom{2}{2}x^{0}y^{2}
\] Calculating the binomial coefficients \((\binom{n}{k})\), we get: \[ x^{2} + 2xy + y^{2} \] This matches our expanded and simplified form. The binomial theorem is especially helpful for expanding higher powers of polynomials efficiently.
(a + b)^n = \sum_{k=0}^{n} \binom{n}{k} a^{n-k} b^k
\] For \((x+y)^{2}\), it looks like this: \[ (x+y)^{2} = \binom{2}{0}x^{2}y^{0} + \binom{2}{1}x^{1}y^{1} + \binom{2}{2}x^{0}y^{2}
\] Calculating the binomial coefficients \((\binom{n}{k})\), we get: \[ x^{2} + 2xy + y^{2} \] This matches our expanded and simplified form. The binomial theorem is especially helpful for expanding higher powers of polynomials efficiently.