Answer
$a.$
Starting with the graph of $f(x)$,
- reflect it about the $y$-axis ... to get $f(-x)$,
$b.$
Starting with the graph of $f(x)$,
- stretch it vertically by factor $3$... to get $ 3f(x)$
Work Step by Step
The exercise is to describe transformations,
so the answer is given in step-by-step form.