Question 858556
THIS PART IS NOT CORRECT-----The first question is wrong.  The arrangement for the grouping symbols and the use of the word, "over", indicate f(x) in your first question is RATIONAL-----THAT PART WAS NOT CORRECT.  
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Much of the rest of your first question's function is imprecise, therefore we do not know which function you really mean.


Now understood more clearly, the square root being present in the numerator forces the function to become irrational for many elements in the domain of x.