Ques 8:
The Volume(V) in cubic feet of an aquarium id modeled by the polynomial function V(x)= 
a) We have to explain that why x =4 is not a possible rational zero.
By Factor theorem, which states that a polynomial f(x) has a factor (x - k) if and only if f(k)=0.
For this , we will substitute the value of x in the given function.



which is not equal to zero.
Therefore, x=4 is not a possible rational zero.
(b) To show that (x-1) is a factor of V(x).
By Factor theorem, which states that a polynomial f(x) has a factor (x - k) if and only if f(k)=0.
Let (x-1)=0
So, x=1.
Substituting x=1 in the given function.


V(1) = 0
Therefore, (x-1) is a factor of V(x).
Now we will factorize the given function.
Dividing the given function by (x-1).
On dividing, we get quotient as 
So, factored form is = 
= 
= 
=
(c) So, the dimensions are 1,2 and -5.