Question

Which is a rational function?

A. y=x^2-x+4
B. 2/x
C. x-3^3/x^2
D. x-5/2

...?

Answer 1

The correct answer is: y=2/x . A rational function is the quotient of two polynomial functions. Notice that (x - 5)/2 can be simplified into a single polynomial function, so it is not a rational function.

Answer 2

A rational function is basically a function which can be defined by a rational fraction, which means that A is definitely not correct.
I'd say C. x-3^3/x^2 is the correct answer because of all these cubes and squares.