Question

Which of the following expressions is a polynomial?

a. x^5+sqrt x^3 +x
b. 1/x^4+1/x^2
c. 5x^ −1
d. 2x^3+x-6/7

Answer 1

is it D?

Answer 2

yes it's D

Answer 3

okay, thanks :)

Answer 4

a polynomial has ALL exponents as nonnegative integers (natural numbers)

in A you have sqrt x^3 which is translated to x^3/2 <--this is obviously NOT a natural number

in B 1/x^4 can be translated as x^-4 <--obviously not positive

in C you have 5x^-1 <--again not positive