1. **Stating the problem:** We are given the sequence 2, 8, 18, 32, 50 and asked to find the pattern of the terms.
2. **Look for a pattern:** Let's denote the $n$th term as $a_n$.
3. **Check differences:** Calculate the first differences:
$$8-2=6, \quad 18-8=10, \quad 32-18=14, \quad 50-32=18$$
4. **Check second differences:** Calculate the differences of the first differences:
$$10-6=4, \quad 14-10=4, \quad 18-14=4$$
Since the second differences are constant (equal to 4), the sequence follows a quadratic pattern.
5. **General quadratic form:**
$$a_n = An^2 + Bn + C$$
6. **Use the first three terms to find $A$, $B$, and $C$:**
\begin{align*}
a_1 &= A(1)^2 + B(1) + C = A + B + C = 2 \\
a_2 &= 4A + 2B + C = 8 \\
a_3 &= 9A + 3B + C = 18
\end{align*}
7. **Solve the system:**
Subtract first from second:
$$4A + 2B + C - (A + B + C) = 8 - 2 \Rightarrow 3A + B = 6$$
Subtract second from third:
$$9A + 3B + C - (4A + 2B + C) = 18 - 8 \Rightarrow 5A + B = 10$$
Subtract the two equations:
$$(5A + B) - (3A + B) = 10 - 6 \Rightarrow 2A = 4 \Rightarrow A = 2$$
Plug $A=2$ into $3A + B = 6$:
$$3(2) + B = 6 \Rightarrow 6 + B = 6 \Rightarrow B = 0$$
Plug $A=2$, $B=0$ into $A + B + C = 2$:
$$2 + 0 + C = 2 \Rightarrow C = 0$$
8. **Final formula:**
$$a_n = 2n^2$$
9. **Verification:**
$$a_1 = 2(1)^2 = 2$$
$$a_2 = 2(2)^2 = 8$$
$$a_3 = 2(3)^2 = 18$$
$$a_4 = 2(4)^2 = 32$$
$$a_5 = 2(5)^2 = 50$$
All terms match the given sequence.
**Answer:** The pattern of the $n$th term is $$a_n = 2n^2$$.
Sequence Pattern A1Ad13
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