Question 1006489
.
What is your question?


----------------------------------------------------------
<U>Comment from student</U>: Find the value of x that must be excluded in the algebraic fraction: y-4/y^2-y-20 — Thanks
----------------------------------------------------------


OK. 


Let us consider the denominator of this function which is a quadratic polynomial p(x) =  {{{y^2-y-20}}}.


It can be factored as p(y) = (y-5)*(y+4).


It has the roots y = 5 and y = -4.


Hence, the domain of the given rational function is the entire number line except two points y = 5 and y = -4, where the function is not defined.