The value of x in the expression, x 2 = 9 is 4.5
9 divided by 2 = 4.5
A polynomial is defined as a collection of variables and constant terms combined by various mathematical operations. The exponents of the variables in a polynomials must be non-negative integers.
If you observe the given options, one of the option (option B) contains a negative exponent. Hence the expression in option B is not a polynomial.
Your question is a little ambiguous, but I am assuming that you meant to say the function 
Thus, I am solving your question based on assuming the function such as

But, it would still clear your concept, no matter what the function is.
Answer:
we conclude that

The graph is also attached.
Step-by-step explanation:
Given the function

We know that the domain of a function is the set of input or argument values for which the function is real and defined.
As the function has no undefined points nor domain constraints.
Thus, the domain is

Therefore, we conclude that

The graph is also attached.
Hey there Smarty!
This would be considered to be a (acute angel) which in this case, we would have to make sure that this whole triangle would equal less than 270 because each angle would be less than

°
If we add/multiply

.
So, we would have to know that was ever this would all add up to be, this would have to be less than 270°
![\left[\begin{array}{ccc}\boxed{\boxed{(2.5+5) \\ \\ (2.5*2.5) \\ (2.5-2) \\ (2.5-1) \\}} \\ \\ this \ would \ be \ why \ I \ would \ say \\ that \ this \ would \ be \ the \ answer \end{array}\right]](https://tex.z-dn.net/?f=%20%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D%5Cboxed%7B%5Cboxed%7B%282.5%2B5%29%20%5C%5C%20%5C%5C%20%282.5%2A2.5%29%20%5C%5C%20%282.5-2%29%20%5C%5C%20%282.5-1%29%20%5C%5C%7D%7D%20%5C%5C%20%5C%5C%20this%20%5C%20would%20%5C%20be%20%5C%20why%20%5C%20I%20%5C%20would%20%5C%20say%20%5C%5C%20that%20%5C%20this%20%5C%20would%20%5C%20be%20%5C%20the%20%5C%20answer%20%5Cend%7Barray%7D%5Cright%5D%20%20)
I truly hope this helps, and also, it's kind of my
first time doing this I hope this would be helpful.
~Jurgen