Domain of a function
Answers are for parents and teachers.
1
Find the domain of y = √(3x + 12).
x ≥ −4
2
Find the domain of y = 2 : (x² − 4).
x ≠ 2 and x ≠ −2
3
Find the domain of y = √(x² − 6x + 8).
x ≤ 2 or x ≥ 4
4
Find the value of y = |x + 1| − 3 at x = 2 and the corner point of its graph.
y(2) = 0; corner point (−1, −3)
5
For y = 1 : √(x − 1), why is x = 1 not in the domain? State the domain.
We need x − 1 > 0 (the root is in the denominator and must not be zero): x > 1.