Answer
Parent function: $y=cosx$
Transformations:
1) $y=2cosx$
2) $y=-2cosx$
3) $y=-2cosx+3$
See image.
Work Step by Step
To graph the function, let's take the parent function and start transformations on it.
(1) Graph the parent function $y=cosx$ (Blue line graph).
(2) Graph $y=2cosx$ by stretching the parent function vertically by a factor of 2 (Blue dotted line graph).
(3) Graph $y=-2cosx$ by reflecting the previous graph about the $x$-axis (Red dotted line graph)
(4) Graph $y=-2cosx+3$ by shifting the previous graph by 3 units upward (Red line graph).
