1. The problem asks for the middle term in the expansion of $ (p + q)^n $ where $ n $ is even.
2. Recall the binomial expansion formula:
$$ (p + q)^n = \sum_{k=0}^n \binom{n}{k} p^{n-k} q^k $$
3. Since $ n $ is even, the number of terms is $ n+1 $, which is odd, so there is a single middle term.
4. The middle term corresponds to the term where $ k = \frac{n}{2} $.
5. Therefore, the middle term is:
$$ T_{\frac{n}{2}+1} = \binom{n}{\frac{n}{2}} p^{n-\frac{n}{2}} q^{\frac{n}{2}} = \binom{n}{\frac{n}{2}} p^{\frac{n}{2}} q^{\frac{n}{2}} $$
6. This term is the coefficient $ \binom{n}{\frac{n}{2}} $ multiplied by $ p^{\frac{n}{2}} q^{\frac{n}{2}} $.
Final answer:
$$ \boxed{\binom{n}{\frac{n}{2}} p^{\frac{n}{2}} q^{\frac{n}{2}}} $$
Middle Term
Step-by-step solutions with LaTeX - clean, fast, and student-friendly.