Determine whether the function x^3+x^2-1 is even, odd or neither.

I thought it was odd because it has one negative sign is this correct

it is neither.

you can test it by taking any +/- value for input
e.g. let x =+2
the expression is 8 + 4 - 1 = 11
let x = -2
the expression should be 11 if the function were even
should be -11 if the function was odd
but it is -8 + 4 - 1 = -5

in general if a function is odd, it consists only of powers with odd exponents
if a function is even it has only even exponents,
so .....