Find the domain of the function fxx47x333x210x25 Write answe
Find the domain of the function f(x)=(x^4-7x^3+3)/(3x^2-10x-25). Write answer in set notation.
Solution
A rational function is undefined if the denominator is equals to 0. So let us first find where the denominator is 0.
hence
3x^2-10x-25 =0
=> 3x^2 -15x+5x -25 =0
=> 3x(x-5) +5(x-5)
=> (3x+5) (x-5)=0
=> x = -5/3 , 5
In order to the given rational function to be defined x should not be equal to 5 and -5/3
hence domain is in set notation:-
{ x element R : x!= 5/3 and x! = 5}

