To check whether a function is odd or even, we simply substitute the argument by its negative version, namely "x" by "-x".
if the expression simplifies to resemble the original expression, that simply means the expression is even. If it resembles the original negative expression, is odd.
well, that doesn't look like the original - 2x³ - 9, so is not even.
and -f(x) would be 2x³ + 9, and that doesn't look like either, so is not odd.
thus is neither.
if the expression simplifies to resemble the original expression, that simply means the expression is even. If it resembles the original negative expression, is odd.
well, that doesn't look like the original - 2x³ - 9, so is not even.
and -f(x) would be 2x³ + 9, and that doesn't look like either, so is not odd.
thus is neither.
