Step-by-step explanation:
The original function is f(x):

And g(x) is the transformed function after a reflection across the y-axis, a translation of 3 units right and 1 unit up.
Step 1. A reflection across the y-axis is represented by:

Step 2. A translation of 3 units to the right is represented by:

Step 3. And a translation of 1 unit up is represented by:

Step 4. Combining these three transformations:

Step 5. Function g(x) is defined as follows:

Which applied to the f(x) function is:

Simplifying the operations:

That is the rule for function g(x).
Answer:
