SOLUTION: Find the Domain of the Rational Function f(X)=X^2-4X-21/X^2+3X+2 Please Help, Thank You

Question 28504: Find the Domain of the Rational Function
f(X)=X^2-4X-21/X^2+3X+2
Please Help,
Thank You
Answer by sdmmadam@yahoo.com(530) (Show Source): You can put this solution on YOUR website!
f(x)=(x^2-4x-21)/(x^2+3x+2)
=[(x-7)(x+3)]/[(x+1)(x+2)] (factorising the nr and dr)
Since division by zero is not defined, the dr [(x+1)(x+2)] SHOULD NOT BE ZERO
And the dr will be zero for either (x+1) = 0 implying x = -1
or for (x+2) = 0 implying x = -2
Therefore x=-2 and x=-3 should not be domain members because if they are there in the domain set f(x) is not defined. That is we cannot find f- image for these two values of x
Therefore we conclude the domain of the given function is the set of all real numbers excepting the values -1 and -2
That is the domain set is the complement of the set {-1,-2} in the real number system R
That is the required domain set is R - {-1,-2}

RELATED QUESTIONS
Find the domain of the rational function. 2 _____ x + 3 Help please? Thank you (answered by Alwayscheerful)

I am not understanding the vertical and horizontal asympote of the rational function. Can (answered by jake_6233)

Find the domain of the rational function: f(x) = (2x^2 - 4) / (3x^2 + 6x -... (answered by funmath)

Find the domain of the rational function f(x)=2x^2-4/3x^2+6x-72 (answered by solver91311)

Find the domain of the rational function f(x) = (x^3 + 2x^2 + x + 1)/(x^2 + 3x +... (answered by rapaljer)

State the domain of the function f(x)= x^2+1/x^2-3x Thank you for your... (answered by josgarithmetic)

Please help me solve the following problem: Find the domain of {{{f(x) = 1/(x^2 - 3x... (answered by scott8148)

Please help me solve the following problem: Find the domain of f(x) = 1/x^2 - 3x -4... (answered by stanbon)

Please help me, I'm so confused! List the possible rational zeros of the function... (answered by jim_thompson5910)