For the AP : `3/2,1/2,-1/2,-3/2,dotdotdot,`write the first term a and the common difference d.

Explanation

To solve the problem, we need to identify the first term \( a \) and the common difference \( d \) of the given arithmetic progression (AP):

\[ \frac{3}{2}, \frac{1}{2}, -\frac{1}{2}, -\frac{3}{2}, \ldots \]

### Step-by-Step Solution:

**Step 1: Identify the first term \( a \)**
The first term of the arithmetic progression is the first number in the sequence.
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