Applying the Binomial Theorem

In this activity, you'll find the expanded form of the binomial expression [tex]\((x+y)^4\)[/tex] using the binomial theorem. Answer the following questions to expand the binomial expression [tex]\((x+y)^4\)[/tex] using the binomial theorem.

[tex]\[
(a+b)^n = a^n + \frac{n}{1!} a^{n-1} b^1 + \frac{n(n-1)}{2!} a^{n-2} b^2 + \frac{n(n-1)(n-2)}{3!} a^{n-3} b^3 + \cdots + b^n
\][/tex]

Part A
Determine the first term of the binomial expansion [tex]\((x+y)^4\)[/tex].



Answer :

To find the first term of the binomial expansion [tex]\((x + y)^4\)[/tex], we can use the binomial theorem. The binomial theorem states that [tex]\((a + b)^n\)[/tex] can be expanded as:

[tex]\[ (a + b)^n = a^n + \binom{n}{1} a^{n-1} b + \binom{n}{2} a^{n-2} b^2 + \cdots + \binom{n}{n-1} a b^{n-1} + b^n \][/tex]

Here, [tex]\(a = x\)[/tex], [tex]\(b = y\)[/tex], and [tex]\(n = 4\)[/tex]. According to the binomial theorem, the first term of the binomial expansion is [tex]\(a^n\)[/tex].

In our specific case:

1. [tex]\(a = x\)[/tex]
2. [tex]\(n = 4\)[/tex]

Therefore, the first term of the expansion is:

[tex]\[ x^n = x^4 \][/tex]

So, the first term of the binomial expansion [tex]\((x + y)^4\)[/tex] is:

[tex]\[ x^4 \][/tex]