To find the common difference \( d \) in the arithmetic sequence, we subtract the first term from the second term.
Given the first few terms:
- First term (\( a_1 \)) = \( \frac{3}{2} \)
- Second term (\( a_2 \)) = \( \frac{1}{2} \)
The common difference \( d \) can be calculated as follows:
\[ d = a_2 - a_1 = \frac{1}{2} - \frac{3}{2} = \frac{1 - 3}{2} = \frac{-2}{2} = -1 \]
Thus, the common difference of the arithmetic sequence is \( d = -1 \).