Do you know what a preimage is first???
Answer:
The function y=cos(x-π) is the left graph
Step-by-step explanation:
y=cos(x-π) represents a horizontal shift to the right by π units from the parent function y=cos(x). Since y=cos(x) starts at the maximum, then shifting the function to the right by π units gives the leftmost graph.
Switch y and x to find the inverse:
x = 3y - 8
Now just solve for y
y = x/3 + 8/3