2020 NOV Afternoon P1 Q4

Let \(f(x) = a\log_{3}{(x - 4)}\), for \(x > 4\), where \(a > 0\).
Point \(\mathrm{A} \ (13, 7) \) lies on the graph of \(f\).

1. Find the value of \(a\).

   [3]

The \(x\)-intercept of the graph of \(f\) is \( (5, 0 )\).

2. On the following grid, sketch the graph of \(f\).

   [3]