Answer:
neither 
Step-by-step explanation:
First we must determine if both x and -x are in the domain of the function 
since it is a polynomial function our first condition is satisfied 
Then we should calculate the image of -x : 
2x(-x)^3 + 3*(-x)² = -2x^3+3x² 
it is not equal to f(x) nor -f(x)