Functions and Relations Quiz

Grade 9 · Math · Quiz

Test your understanding of functions, function notation, domain, and range.

Questions

If f(x) = 5x − 4, what is f(3)?
1. 11
2. 15
3. 19
4. 7
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Answer: 11
f(3) = 5(3) − 4 = 15 − 4 = 11.
Every function is also a relation.
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Answer: True
A function is a specific type of relation with the one-output-per-input restriction.
Which ordered pair set is NOT a function?
1. {(1,4),(2,5),(3,6)}
2. {(0,1),(1,1),(2,1)}
3. {(3,1),(3,2),(4,5)}
4. {(−1,2),(0,3),(1,4)}
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Answer: {(3,1),(3,2),(4,5)}
x = 3 maps to both 1 and 2 — two outputs for one input.
If h(x) = x² + 2, then h(0) = ___.
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Answer: 2
h(0) = 0² + 2 = 2.
What is the range of f(x) = |x| for all real x?
1. All real numbers
2. All negative numbers
3. All non-negative numbers
4. All positive numbers
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Answer: All non-negative numbers
Absolute value is always ≥ 0, so the range is [0, ∞).
The vertical line test can determine whether a graph represents a function.
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Answer: True
If any vertical line intersects the graph more than once, it is not a function.
If f(x) = 3x + 1 and f(a) = 13, what is a?
1. 3
2. 4
3. 5
4. 6
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Answer: 4
3a + 1 = 13 → 3a = 12 → a = 4.
The set of all possible output values of a function is called the ___.
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Answer: range
Range = all possible outputs (y-values) of a function.
A circle graphed on the coordinate plane is:
1. Always a function
2. Never a function
3. A function only for positive x
4. A function only when the radius is 1
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Answer: Never a function
A vertical line through a circle intersects it at two points, failing the vertical line test.
If g(t) = 2t − 7, what is g(−2)?
1. −11
2. −3
3. 3
4. 11
Show answer
Answer: −11
g(−2) = 2(−2) − 7 = −4 − 7 = −11.

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