we need to find that which of the functions are odd.
as we know that if the highest degree of the polynomial is odd then the function will be odd.
so now we have f(x)=x^3-x^2
here the highest degree is 3 which is an odd number so the f(x)=x^3-x^2 is odd
next have we f(x)=x^5-3x^3+2x.
here we have highest degree is 5 which is an odd function.
next we have f(x) =4x+9 which is not odd function because if we check f(-x)=-f(x) it wont equals
finally we are having f(x)=1/x which mean x^-1 which is also odd function. or else we can check by f(-x)=-f(x).which mean we need to plug -x in place of x and we need to check for whether it is equal to -f(x).