Questions: Find the specified nth term in the expansion of the binomial.
(x+y)^12, n=4
Transcript text: Find the specified $n$th term in the expansion of the binomial.
\[
(x+y)^{12}, \quad n=4
\]
Solution
Solution Steps
Step 1: Identify Parameters
We are tasked with finding the 4th term in the expansion of \((x+y)^{12}\). According to the binomial theorem, the \( k \)th term in the expansion is given by:
\[
T_k = \binom{n}{k} x^{n-k} y^k
\]
Here, \( n = 12 \) and for the 4th term, \( k = 3 \).
Step 2: Calculate the Binomial Coefficient
We calculate the binomial coefficient \(\binom{12}{3}\):
\[
\binom{12}{3} = 220
\]
Step 3: Determine the Powers of \( x \) and \( y \)
For the 4th term, we find the powers of \( x \) and \( y \):
\[
x^{12-3} = x^9 \quad \text{and} \quad y^3 = y^3
\]
Step 4: Formulate the 4th Term
Now we can express the 4th term:
\[
T_4 = \binom{12}{3} x^{9} y^{3} = 220 x^{9} y^{3}
\]
Final Answer
The 4th term in the expansion of \((x+y)^{12}\) is
\[
\boxed{220 x^{9} y^{3}}
\]