Question

how many zeroes does cubic polynomial has?

Answer 1

Regardless of odd or even, any polynomial of positive order can have a maximum number of zeros equal to its order. For example, a cubic function can have as many as three zeros, but no more.

Answer 2

A cubic polynomial can have up to 3 zeroes

$y= x^3$ has only 1 zero

Whereas $y=x^3 -2x$ has 3 zeros