The domain for which the function behaves as expected is when x > 0. The function produces invalid output values for negative inputs and zero.

To approximate the function using Python code, let's calculate the slope and intercept for the linear behavior we have observed. Using the input-output pairs (2, 6.958328556061463) and (4, 17.016657112122925), we can compute the slope and intercept as follows:

slope = (17.016657112122925 - 6.958328556061463) / (4 - 2)
intercept = 6.958328556061463 - (slope * 2)

The function can then be approximated using this linear formula:

