Mathematics · Grades 10–12
Functions: domains and transformations
Over real numbers, denominators cannot be zero and even-root inputs must be nonnegative.
Understand the idea
Domain restrictions
Over real numbers, denominators cannot be zero and even-root inputs must be nonnegative.
Function notation
f(x) denotes an output, not f multiplied by x.
Examples and reasoning
For f(x) = 1/(x − 4), which input is excluded?
4
4
For f(x) = √(x − 3), the real domain is
x ≥ 3
x ≥ 3
Check your understanding
The graph y = (x − 2)² is y = x² shifted
- 2 units right
- 2 units left
- 2 units down
- 2 units up
The graph y = x² + 5 is y = x² shifted
- 5 units up
- 5 units right
- 5 units left
- 5 units down
If f(x) = 2x + 1 and g(x) = x², find f(g(3)).
An inverse function over a specified domain requires the original function to be
- one-to-one on that domain
- always positive
- always a straight line
- defined at every real number
Answers and marking notes
Answers and marking notes
- 2 units right
2 units right
- 5 units up
5 units up
- 19
g(3) = 9; f(9) = 19.
- one-to-one on that domain
one-to-one on that domain
Further reading and review references
These are reference links, not copied exercises, institutional endorsement or proof of independent review.
Learning preview · teacher review required. Grade bands are approximate, not official curriculum alignment.