what are the answers to the attachment and how did you get that answer

SOLUTION
A Polynomials are sums of terms of the form
[tex]k.x^n[/tex]where k is any number and n is a positive integer. Hence n must be a positive whole number
[tex]\begin{gathered} x^2+1 \\ is\text{ a polynomial } \\ \text{This is because the exponent or power (2) is a positive whole number } \end{gathered}[/tex][tex]\begin{gathered} x^{\frac{1}{2}}+1 \\ is\text{ not a polynomial } \\ \text{This is because polynomial cannot contain a fractional exponent or } \\ \text{power. }\frac{1}{2}\text{ is a fraction } \\ \text{hence }x^{\frac{1}{2}}+1\text{ is not a polynomial } \end{gathered}[/tex][tex]\begin{gathered} \frac{x}{3} \\ is\text{ a polynomial } \\ \text{This is because }x\text{ can also be written as }x^1 \\ so,\text{ the power or exponent (1) is a whole number. } \\ \text{Hence }\frac{x}{3}\text{ is a polynomial } \end{gathered}[/tex]