CSCAPrep
Reviewed CSCA Mathematics question · Hard

Consider the function f(x) = sqrt(6 - x) / (x^2 - 7x + 10). What is the domain of f?

  1. (-∞, 2) ∪ (2, 5) ∪ (5, 6]
  2. (-∞, 2) ∪ (2, 5) ∪ (5, ∞)
  3. (-∞, 6]
  4. (-∞, 2) ∪ (2, 5) ∪ (5, 6)
Show the answer and explanation

Correct answer

A. (-∞, 2) ∪ (2, 5) ∪ (5, 6]

Principle or equation

The domain of a function defined by a fraction with a square root in the numerator requires the radicand to be nonnegative and the denominator to be nonzero.

Why this answer is correct

The radicand 6 - x must be ≥ 0, so x ≤ 6. The denominator x^2 - 7x + 10 = (x - 2)(x - 5) must not be zero, so x ≠ 2 and x ≠ 5. Combining these gives (-∞, 2) ∪ (2, 5) ∪ (5, 6].

Example

For f(x) = sqrt(4 - x)/(x - 1), domain is (-∞, 1) ∪ (1, 4].

This published item includes a stored explanation and passed the platform’s publication workflow. It is independent preparation material, not a claim of an official or recalled examination question.

Related practice questions