You're probably looking for the "maximal domain", i.e. the largest subset of IR for which f(x) is real (so finite).
You have to 'watch out' for:
- denominators becoming 0 for some x-value(s).
- negative expressions under (square) roots.
What is the domain of each of the following functions?
1.) f(x) = 3x + 9
2.) f(x) = (4x^3 + 4) / (x ( x + 2) (x - 1))
3.) f(x) = x^3 - x^2 + x - 2 EDIT this is minus sorry
ur going to make this undefined ryt?
Help ive tried learning but Visual Calculus - Drill - Domains of Functions
is different from # 1 and # 3 questions
Hi,
you have to look for those real numbers x for which the function f will give real values.
As TD! has pointed out there are only a few restrictions. You don't deal with square-roots or logarithms. So the only restriction could be that the denominator becomes zero.
1.) D = x Є IR that means: no restrictions
2.) D = x Є IR\{-2, 0, 1} becaus for these numbers the denominator becomes zero
3.) D= x Є IR that means: no restrictions
EB