Answer:
A- When they are inverse functions
C- when they are equal for all values of x
Step-by-step explanation:
The order of function application in a composition can be reversed if ...
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In the first case, the composition gives an output equal to its input for the functions in either order.
In the second case, you cannot tell the functions apart, since they produce the same output for the same input. Hence, you can't tell if they are reordered or not.