# Math Help - What kind of function is this

1. ## What kind of function is this

I have to determine what kind of function these are and so have i have deteremined what they are NOT

2x^-3 + 5x^-2 +6

2x^2 + t^(1/3)

__GR__
x^3 - 8

I have determined they are all neither polynomial or rational
i believe the 2nd is a power function
how do i tell which is which?? thanks

2. The first one definitely is a rational function: it is the same as $\frac{6x^3+ 5x+ 2}{x^3}$. I'm not sure what you mean by a "power function". The second is a polynomial in x and a radical function in t. I have no idea what the "GR" is supposed to indicate. If they are just constants then the third is also a rational function.