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Introduction to Functions — Easy Worksheet 1
Grade 8 · MathSheets Name: ____________________ Date: __________
Answer each question.
How to solve
A relation is a function if every x-value has only one y-value, so check whether any x-value repeats with a different y; if it does, the answer is No. To find f(x) from a table, find the pair with that x-value and read its y-value.
Example
Is the relation in the table a function? (Yes or No)
| x | y |
|---|---|
| 7 | 13 |
| 4 | 6 |
| 2 | 1 |
| 3 | 11 |
Answer: Yes
| x | y |
|---|---|
| 2 | 4 |
| 5 | 4 |
| 3 | 9 |
| 2 | 18 |
Not quite. The answer is
💡 The input x = 2 appears twice, once with output 4 and once with output 18. A function gives each input only one output, so this is not a function: No.
✓ Correct!
Not quite. The answer is
💡 The input x = 2 appears twice, once with output 4 and once with output 18. A function gives each input only one output, so this is not a function: No.
💡 How to solve: Introduction to Functions
A relation is a function if every x-value has only one y-value, so check whether any x-value repeats with a different y; if it does, the answer is No. To find f(x) from a table, find the pair with that x-value and read its y-value.
Try a similar one
Is the relation in the table a function? (Yes or No)
| x | y |
|---|---|
| 1 | 20 |
| 5 | 12 |
| 8 | 19 |
| 8 | 4 |
✓ You've got it! Press Next to keep going. Not yet — the answer is . Read the steps above once more.
| x | y |
|---|---|
| 4 | 9 |
| 8 | 14 |
| 5 | 12 |
| 6 | 7 |
Not quite. The answer is
💡 f(8) means the output when the input is 8. Find x = 8 in the table: its y-value is 14. So f(8) = 14.
✓ Correct!
Not quite. The answer is
💡 f(8) means the output when the input is 8. Find x = 8 in the table: its y-value is 14. So f(8) = 14.
💡 How to solve: Introduction to Functions
A relation is a function if every x-value has only one y-value, so check whether any x-value repeats with a different y; if it does, the answer is No. To find f(x) from a table, find the pair with that x-value and read its y-value.
Try a similar one
Is the relation in the table a function? (Yes or No)
| x | y |
|---|---|
| 8 | 17 |
| 2 | 14 |
| 1 | 8 |
| 2 | 15 |
✓ You've got it! Press Next to keep going. Not yet — the answer is . Read the steps above once more.
| x | y |
|---|---|
| 8 | 17 |
| 1 | 9 |
| 4 | 6 |
| 4 | 3 |
Not quite. The answer is
💡 The input x = 4 appears twice, once with output 6 and once with output 3. A function gives each input only one output, so this is not a function: No.
✓ Correct!
Not quite. The answer is
💡 The input x = 4 appears twice, once with output 6 and once with output 3. A function gives each input only one output, so this is not a function: No.
💡 How to solve: Introduction to Functions
A relation is a function if every x-value has only one y-value, so check whether any x-value repeats with a different y; if it does, the answer is No. To find f(x) from a table, find the pair with that x-value and read its y-value.
Try a similar one
Is the relation in the table a function? (Yes or No)
| x | y |
|---|---|
| 5 | 19 |
| 8 | 9 |
| 4 | 6 |
| 5 | 5 |
✓ You've got it! Press Next to keep going. Not yet — the answer is . Read the steps above once more.
| x | y |
|---|---|
| 1 | 18 |
| 6 | 10 |
| 2 | 8 |
| 5 | 9 |
Not quite. The answer is
💡 f(1) means the output when the input is 1. Find x = 1 in the table: its y-value is 18. So f(1) = 18.
✓ Correct!
Not quite. The answer is
💡 f(1) means the output when the input is 1. Find x = 1 in the table: its y-value is 18. So f(1) = 18.
💡 How to solve: Introduction to Functions
A relation is a function if every x-value has only one y-value, so check whether any x-value repeats with a different y; if it does, the answer is No. To find f(x) from a table, find the pair with that x-value and read its y-value.
Try a similar one
Is the relation in the table a function? (Yes or No)
| x | y |
|---|---|
| 8 | 6 |
| 1 | 11 |
| 6 | 18 |
| 7 | 15 |
✓ You've got it! Press Next to keep going. Not yet — the answer is . Read the steps above once more.
| x | y |
|---|---|
| 8 | 10 |
| 4 | 15 |
| 3 | 2 |
| 8 | 15 |
Not quite. The answer is
💡 The input x = 8 appears twice, once with output 10 and once with output 15. A function gives each input only one output, so this is not a function: No.
✓ Correct!
Not quite. The answer is
💡 The input x = 8 appears twice, once with output 10 and once with output 15. A function gives each input only one output, so this is not a function: No.
💡 How to solve: Introduction to Functions
A relation is a function if every x-value has only one y-value, so check whether any x-value repeats with a different y; if it does, the answer is No. To find f(x) from a table, find the pair with that x-value and read its y-value.
Try a similar one
Is the relation in the table a function? (Yes or No)
| x | y |
|---|---|
| 7 | 12 |
| 2 | 5 |
| 1 | 19 |
| 4 | 8 |
✓ You've got it! Press Next to keep going. Not yet — the answer is . Read the steps above once more.
| x | y |
|---|---|
| 3 | 7 |
| 1 | 19 |
| 5 | 7 |
| 8 | 10 |
Not quite. The answer is
💡 f(8) means the output when the input is 8. Find x = 8 in the table: its y-value is 10. So f(8) = 10.
✓ Correct!
Not quite. The answer is
💡 f(8) means the output when the input is 8. Find x = 8 in the table: its y-value is 10. So f(8) = 10.
💡 How to solve: Introduction to Functions
A relation is a function if every x-value has only one y-value, so check whether any x-value repeats with a different y; if it does, the answer is No. To find f(x) from a table, find the pair with that x-value and read its y-value.
Try a similar one
Is the relation in the table a function? (Yes or No)
| x | y |
|---|---|
| 2 | 1 |
| 7 | 17 |
| 3 | 12 |
| 1 | 15 |
✓ You've got it! Press Next to keep going. Not yet — the answer is . Read the steps above once more.
| x | y |
|---|---|
| 1 | 4 |
| 4 | 11 |
| 2 | 19 |
| 5 | 1 |
Not quite. The answer is
💡 The inputs 1, 4, 2 and 5 are all different, so each input has exactly one output. The relation is a function: Yes.
✓ Correct!
Not quite. The answer is
💡 The inputs 1, 4, 2 and 5 are all different, so each input has exactly one output. The relation is a function: Yes.
💡 How to solve: Introduction to Functions
A relation is a function if every x-value has only one y-value, so check whether any x-value repeats with a different y; if it does, the answer is No. To find f(x) from a table, find the pair with that x-value and read its y-value.
Try a similar one
Is the relation in the table a function? (Yes or No)
| x | y |
|---|---|
| 7 | 14 |
| 2 | 11 |
| 4 | 17 |
| 5 | 9 |
✓ You've got it! Press Next to keep going. Not yet — the answer is . Read the steps above once more.
| x | y |
|---|---|
| 5 | 14 |
| 6 | 10 |
| 8 | 13 |
| 1 | 16 |
Not quite. The answer is
💡 f(6) means the output when the input is 6. Find x = 6 in the table: its y-value is 10. So f(6) = 10.
✓ Correct!
Not quite. The answer is
💡 f(6) means the output when the input is 6. Find x = 6 in the table: its y-value is 10. So f(6) = 10.
💡 How to solve: Introduction to Functions
A relation is a function if every x-value has only one y-value, so check whether any x-value repeats with a different y; if it does, the answer is No. To find f(x) from a table, find the pair with that x-value and read its y-value.
Try a similar one
Is the relation in the table a function? (Yes or No)
| x | y |
|---|---|
| 3 | 18 |
| 8 | 2 |
| 4 | 12 |
| 8 | 7 |
✓ You've got it! Press Next to keep going. Not yet — the answer is . Read the steps above once more.
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Introduction to Functions — Easy Worksheet 1
Answer each question.