## Algebra and Trigonometry 10th Edition

The graph labeled as (d) matches with $a_n=18(-\frac{3}{2})^{n-1}$
$a_n=a_1r^{n-1}$ $a_n=18(-\frac{3}{2})^{n-1}$ $a_1=18$ $r=-\frac{3}{2}$ Since $a_1\gt0$ and $r\lt-1$, the terms of the sequence are alternating between positive and negative with their absolute values increasing.