SOLUTION: let a function f be defined by f(x) = x^2-2x-3/x^2+2x+3 i) determine the domain of f(x) ii) find the range of f(x)

Algebra ->  Exponential-and-logarithmic-functions -> SOLUTION: let a function f be defined by f(x) = x^2-2x-3/x^2+2x+3 i) determine the domain of f(x) ii) find the range of f(x)      Log On


   



Question 976058: let a function f be defined by
f(x) = x^2-2x-3/x^2+2x+3
i) determine the domain of f(x)
ii) find the range of f(x)

Answer by josgarithmetic(39618) About Me  (Show Source):
You can put this solution on YOUR website!
Like this:
f(x) = (x^2-2x-3)/(x^2+2x+3)

Which will properly render as f%28x%29=%28x%5E2-2x-3%29%2F%28x%5E2%2B2x%2B3%29.

Factor as much as possible.

%28%28x-3%29%28x%2B1%29%29%2F%28x%5E2%2B2x%2B3%29

Only two critical x values. Denominator is positive everywhere and has no real roots, so no
vertical asymptotes. Numerator gives f(x) its roots, which are 3 and -1. The numerator is
equivalent itself to a parabola, and in this example, f is negative between the roots and positive
outside the interval which the roots bind.

Domain: All real numbers.

The function f(x) is not a parabola. There is a minimum, and a horizontal asymptote. (Degree is two
for both numerator and denominator).



Only two critical x values. Denominator is positive everywhere and has no real roots, so no
vertical asymptotes. Numerator gives f(x) its roots, which are 3 and -1. The numerator is
equivalent itself to a parabola, and in this example, f is negative between the roots and positive
outside the interval which the roots bind.

Domain: All real numbers.

The function f(x) is not a parabola. There is a minimum, and a horizontal asymptote. (Degree is two
for both numerator and denominator).

graph%28300%2C300%2C-5%2C5%2C-5%2C5%2C%28x%5E2-2x-3%29%2F%28x%5E2%2B2x%2B3%29%29