All questions
Question 1
The table gives outputs of a function f that has an inverse. Since points swap, (x,f(x)) on f corresponds to (f(x),x) on f−1. Use the table to find f−1(13).
| x | f(x) |
|---|
| 2 | 1 |
| 4 | 6 |
| 6 | 10 |
| 7 | 13 |
| 9 | 18 |
- 7 (correct answer)
- 6
- 13
- 9
Explanation: This question tests your ability to read values of an inverse function from a table or graph using the fundamental property that inverses swap inputs and outputs. If f has a table or graph showing its (x, y) pairs, then f⁻¹ has the same pairs but swapped: every (x, y) on f becomes (y, x) on f⁻¹. So to find f⁻¹(a), you don't need the inverse's table or graph—just find where y = a in f's representation and read the corresponding x-value. That x is your answer! For example, if f's table shows x = 3 gives y = 7, then f⁻¹(7) = 3. The inverse reverses the input-output relationship. To find f^{-1}(13), look in the f(x) column for the value 13; you'll see it's paired with x=7 in the table. Choice C correctly finds f⁻¹(13) = 7 by reading from the table properly. It's easy to misread and pick a nearby value like 6 or 9, but always verify the exact match in the output column— excellent work persisting through this! Table reading strategy for f⁻¹(a): (1) Look in the f(x) column (the outputs) for the value a, (2) When you find a, look at the x-value in that same row, (3) That x-value is f⁻¹(a). Example: table shows x: 1, 2, 3, 4 and f(x): 5, 9, 13, 17. To find f⁻¹(13), scan the f(x) column for 13 (found in row 3), read x from that row (x = 3), so f⁻¹(13) = 3. The swap happens automatically when you read this way!
Question 2
A one-to-one function f is shown by the table, so f has an inverse. Use the table to find f−1(12). (Look for the output 12 in the f(x) column; the corresponding x is the inverse value.)
| x | f(x) |
|---|
| 0 | 1 |
| 3 | 6 |
| 5 | 10 |
| 6 | 12 |
| 8 | 16 |
- f−1(12)=12
- f−1(12)=5
- f−1(12)=6 (correct answer)
- f−1(12)=8
Explanation: This question tests your ability to read values of an inverse function from a table or graph using the fundamental property that inverses swap inputs and outputs. If f has a table or graph showing its (x, y) pairs, then f⁻¹ has the same pairs but swapped: every (x, y) on f becomes (y, x) on f⁻¹. So to find f⁻¹(a), you don't need the inverse's table or graph—just find where y = a in f's representation and read the corresponding x-value. That x is your answer! For example, if f's table shows x = 3 gives y = 7, then f⁻¹(7) = 3. The inverse reverses the input-output relationship. Looking for f⁻¹(12), I scan the f(x) column for the value 12: f(0) = 1, f(3) = 6, f(5) = 10, f(6) = 12, f(8) = 16. Found it! When x = 6, f(x) = 12. Therefore, f⁻¹(12) = 6. Choice C correctly finds f⁻¹(12) = 6 by locating the row where f(x) = 12 and reading the corresponding x-value. Choice A incorrectly assumes f⁻¹(12) = 12, which would require f(12) = 12, but 12 isn't even an input in the table. Table reading strategy for f⁻¹(a): (1) Look in the f(x) column (the outputs) for the value a, (2) When you find a, look at the x-value in that same row, (3) That x-value is f⁻¹(a). The process naturally reverses the function's action!
Question 3
A one-to-one function f is shown by the table, so f has an inverse. Use the table to evaluate f−1(21). (Because inverse pairs swap, if f(x)=21 then f−1(21)=x.)
| x | f(x) |
|---|
| 2 | 9 |
| 4 | 13 |
| 6 | 17 |
| 8 | 21 |
| 10 | 25 |
- f−1(21)=8 (correct answer)
- f−1(21)=6
- f−1(21)=10
- f−1(21)=21
Explanation: This question tests your ability to read values of an inverse function from a table or graph using the fundamental property that inverses swap inputs and outputs. If f has a table or graph showing its (x, y) pairs, then f⁻¹ has the same pairs but swapped: every (x, y) on f becomes (y, x) on f⁻¹. So to find f⁻¹(a), you don't need the inverse's table or graph—just find where y = a in f's representation and read the corresponding x-value. That x is your answer! For example, if f's table shows x = 3 gives y = 7, then f⁻¹(7) = 3. The inverse reverses the input-output relationship. To evaluate f⁻¹(21), I scan the f(x) column for 21: f(2) = 9, f(4) = 13, f(6) = 17, f(8) = 21, f(10) = 25. Found it! When x = 8, f(x) = 21. Therefore, f⁻¹(21) = 8. Choice C correctly finds f⁻¹(21) = 8 by locating where f(x) = 21 in the table. Choice A incorrectly assumes f⁻¹(21) = 21, which would require f(21) = 21, but 21 isn't even an input value in the table. Table reading strategy for f⁻¹(a): (1) Look in the f(x) column (the outputs) for the value a, (2) When you find a, look at the x-value in that same row, (3) That x-value is f⁻¹(a). The swap happens automatically when you read this way!
Question 4
Functions s and t are inverses of each other. If s(3)=7 and s(5)=2, what is the value of t(7)−t(2)?
- −2 (correct answer)
- 2
- 5
- 9
Explanation: Since s and t are inverses, t=s−1. From s(3)=7, we get t(7)=s−1(7)=3. From s(5)=2, we get t(2)=s−1(2)=5. Therefore, t(7)−t(2)=3−5=−2. Choice B gives ∣t(7)−t(2)∣. Choice C gives t(2)−t(7). Choice D gives t(7)+t(2)+3. Question 5
Function k has an inverse, and the following values are known: k(1)=3, k(4)=−2, and k(7)=0. What is k−1(−2)+k−1(0)?
- 11 (correct answer)
- −2
- 3
- 5
Explanation: From k(4)=−2, we get k−1(−2)=4. From k(7)=0, we get k−1(0)=7. Therefore, k−1(−2)+k−1(0)=4+7=11. Choice B results from adding the output values −2+0. Choice C results from using k(1)=3 incorrectly. Choice D results from computing k−1(−2)+k−1(3)=4+1. Question 6
The table gives values of a one-to-one function f, so f has an inverse. Use the table to find f−1(−4). (If (a,b) is on f, then (b,a) is on f−1.)
| x | f(x) |
|---|
| -3 | 5 |
| -1 | 1 |
| 0 | -2 |
| 2 | -4 |
| 4 | -7 |
- f−1(−4)=2 (correct answer)
- f−1(−4)=−4
- f−1(−4)=0
- f−1(−4)=4
Explanation: This question tests your ability to read values of an inverse function from a table or graph using the fundamental property that inverses swap inputs and outputs. If f has a table or graph showing its (x, y) pairs, then f⁻¹ has the same pairs but swapped: every (x, y) on f becomes (y, x) on f⁻¹. So to find f⁻¹(a), you don't need the inverse's table or graph—just find where y = a in f's representation and read the corresponding x-value. That x is your answer! For example, if f's table shows x = 3 gives y = 7, then f⁻¹(7) = 3. The inverse reverses the input-output relationship. To find f⁻¹(-4), I need to locate -4 in the f(x) column. Scanning down: f(-3) = 5, f(-1) = 1, f(0) = -2, f(2) = -4, f(4) = -7. I found it! When x = 2, f(x) = -4. Therefore, f⁻¹(-4) = 2. Choice A correctly finds f⁻¹(-4) = 2 by identifying that f(2) = -4 in the table. Choice B incorrectly assumes f⁻¹(-4) = -4, missing the fundamental swap property of inverses. Table reading strategy for f⁻¹(a): (1) Look in the f(x) column (the outputs) for the value a, (2) When you find a, look at the x-value in that same row, (3) That x-value is f⁻¹(a). Remember: you're working backwards from output to input!
Question 7
A one-to-one function f is given by the table, so f has an inverse. What is f−1(14)?
| x | f(x) |
|---|
| 1 | −2 |
| 2 | 4 |
| 3 | 9 |
| 4 | 14 |
| 5 | 20 |
- f−1(14)=14
- f−1(14)=20
- f−1(14)=5
- f−1(14)=4 (correct answer)
Explanation: This question tests your ability to read values of an inverse function from a table or graph using the fundamental property that inverses swap inputs and outputs. If f has a table or graph showing its (x, y) pairs, then f⁻¹ has the same pairs but swapped: every (x, y) on f becomes (y, x) on f⁻¹. So to find f⁻¹(a), you don't need the inverse's table or graph—just find where y = a in f's representation and read the corresponding x-value. That x is your answer! For example, if f's table shows x = 3 gives y = 7, then f⁻¹(7) = 3. The inverse reverses the input-output relationship. Looking for f⁻¹(14), I scan the f(x) column and find f(4) = 14. This means when x = 4, the output is 14, so f⁻¹(14) = 4. Choice B correctly finds f⁻¹(14) = 4 by reading from the table that f(4) = 14 and applying the swap principle. Choice D incorrectly reads 20 from the table, which is actually f(5), not related to finding f⁻¹(14). Table reading strategy for f⁻¹(a): (1) Look in the f(x) column (the outputs) for the value a, (2) When you find a, look at the x-value in that same row, (3) That x-value is f⁻¹(a). Remember, you're working backwards—from output to input—which is exactly what an inverse function does!
Question 8
The table gives values of a one-to-one function f, so f has an inverse. Because inverse functions swap inputs and outputs, (a,b) on f corresponds to (b,a) on f−1. Use the table to determine f−1(−2).
- f−1(−2)=0
- f−1(−2)=−2
- f−1(−2)=2
- f−1(−2)=−1
Explanation: This question tests your ability to read values of an inverse function from a table or graph using the fundamental property that inverses swap inputs and outputs. If f has a table or graph showing its (x, y) pairs, then f⁻¹ has the same pairs but swapped: every (x, y) on f becomes (y, x) on f⁻¹. So to find f⁻¹(a), you don't need the inverse's table or graph—just find where y = a in f's representation and read the corresponding x-value. That x is your answer! The inverse reverses the input-output relationship. To find f⁻¹(-2), I need to locate -2 in the f(x) column and read the corresponding x-value. Looking at the table, when x = 0, f(x) = -2. Therefore, f⁻¹(-2) = 0. Choice A correctly finds f⁻¹(-2) = 0 by identifying that f(0) = -2 in the table. Choice B incorrectly suggests f⁻¹(-2) = -2, which is the common mistake of thinking a function's inverse at a point equals that point—but this would only be true if the point lies on the line y = x. Table reading strategy for f⁻¹(a): (1) Look in the f(x) column (the outputs) for the value a, (2) When you find a, look at the x-value in that same row, (3) That x-value is f⁻¹(a). In this case, -2 appears in the f(x) column when x = 0, so f⁻¹(-2) = 0.
Question 9
The table gives values of a one-to-one function f, so f has an inverse. Use the table to determine f−1(−4).
- f−1(−4)=3
- f−1(−4)=−4
- f−1(−4)=5
- f−1(−4)=8
Explanation: This question tests your ability to read values of an inverse function from a table or graph using the fundamental property that inverses swap inputs and outputs. If f has a table or graph showing its (x, y) pairs, then f⁻¹ has the same pairs but swapped: every (x, y) on f becomes (y, x) on f⁻¹. So to find f⁻¹(a), you don't need the inverse's table or graph—just find where y = a in f's representation and read the corresponding x-value. That x is your answer! For example, if f's table shows x = 3 gives y = 7, then f⁻¹(7) = 3. The inverse reverses the input-output relationship. To find f⁻¹(-4), I scan the f(x) column for -4. I see that f(3) = -4, which means when x = 3, the output is -4. Therefore, f⁻¹(-4) = 3. Choice A correctly finds f⁻¹(-4) = 3 by recognizing that since f(3) = -4, the inverse must map -4 back to 3. Choice B incorrectly assumes f⁻¹(-4) = -4, which would mean -4 is a fixed point, but the table shows f(-4) is not even defined. Table reading strategy for f⁻¹(a): (1) Look in the f(x) column (the outputs) for the value a, (2) When you find a, look at the x-value in that same row, (3) That x-value is f⁻¹(a).
Question 10
The graph shows function r(x). Based on the graph, what is r−1(0)+r−1(2)?
- 1
- 2
- 4 (correct answer)
- 6
Explanation: To find r−1(0), locate where the graph has a y-value of 0, which occurs at x=−1. So r−1(0)=−1. To find r−1(2), locate where the graph has a y-value of 2, which occurs at x=5. So r−1(2)=5. Therefore, r−1(0)+r−1(2)=−1+5=4. Choice A results from adding the output values 0+2−1. Choice B results from counting intercepts incorrectly. Choice D results from using r−1(2)=4 instead of 5. Question 11
Based on the table shown, what is the value of g−1(5)?
- −1
- 2
- 3 (correct answer)
- 8
Explanation: To find g−1(5), we need to find the input value that produces an output of 5. From the table, g(3)=5, so g−1(5)=3. Choice A gives g−1(−1) instead of g−1(5). Choice B gives g−1(8). Choice D gives g(5) instead of g−1(5). Question 12
The table shows some values of function p(x). If p has an inverse, which of the following could be the value of p(6)?
- 1
- 3
- 5
- 9 (correct answer)
Explanation: For p to have an inverse, each output value must correspond to exactly one input value. The table shows outputs 1, 3, and 5 are already used, so p(6) cannot equal any of these values. Only 9 is not already an output value in the table. Choices A, B, and C would create repeated output values, violating the requirement for an inverse function. Question 13
From the graph shown, if f−1(1)=−2, what is the value of f(−2)⋅f−1(−1)?
- −3
- 2
- 3 (correct answer)
- 6
Explanation: Given f−1(1)=−2, we know f(−2)=1. From the graph, we can read that f(3)=−1, so f−1(−1)=3. Therefore, f(−2)⋅f−1(−1)=1⋅3=3. Choice A results from using f−1(−1)=−3. Choice B results from computing f−1(1)+f(0)=−2+4. Choice D results from using f(−2)=−2 instead of 1. Question 14
The graph shows function h(x). If h−1(4)=2, which point must be on the graph of h(x)?
- (2,4) (correct answer)
- (4,2)
- (−2,4)
- (2,−4)
Explanation: If h−1(4)=2, then by definition of inverse functions, h(2)=4. This means the point (2,4) is on the graph of h(x). Choice B confuses the roles of input and output. Choice C uses the wrong sign for the x-coordinate. Choice D uses the wrong sign for the y-coordinate. Question 15
The function f is one-to-one, so it has an inverse. A point on the graph of f is (7,−3). Using the fact that (a,b) on f corresponds to (b,a) on f−1, what is f−1(−3)?
- f−1(−3)=−3
- f−1(−3)=7 (correct answer)
- f−1(−3)=3
- f−1(−3)=−7
Explanation: This question tests your ability to read values of an inverse function from given information using the fundamental property that inverses swap inputs and outputs. If f has a point (a, b), then f⁻¹ has the point (b, a)—every (x, y) on f becomes (y, x) on f⁻¹. So to find f⁻¹(b), you look for the point on f where y = b and read the x-coordinate. Given that (7, -3) is on the graph of f, this means f(7) = -3. By the inverse relationship, this tells us that f⁻¹(-3) = 7. The coordinates swap! Choice B correctly identifies f⁻¹(-3) = 7 by recognizing that the point (7, -3) on f becomes the point (-3, 7) on f⁻¹. Choice A incorrectly suggests f⁻¹(-3) = -3, which would require the point (-3, -3) to be on f. Remember: the inverse function reverses the input-output relationship. If f takes 7 to -3, then f⁻¹ takes -3 back to 7. This swapping property is fundamental to understanding inverse functions!
Question 16
The function f is one-to-one and has an inverse. Use the table to find f−1(0).
| x | f(x) |
|---|
| −3 | −5 |
| −1 | −2 |
| 2 | 0 |
| 4 | 3 |
| 7 | 8 |
- 2 (correct answer)
- 4
- 0
- −2
Explanation: This question tests your ability to read values of an inverse function from a table or graph using the fundamental property that inverses swap inputs and outputs. If f has a table or graph showing its (x, y) pairs, then f⁻¹ has the same pairs but swapped: every (x, y) on f becomes (y, x) on f⁻¹. So to find f⁻¹(a), you don't need the inverse's table or graph—just find where y = a in f's representation and read the corresponding x-value. That x is your answer! For example, if f's table shows x = 3 gives y = 7, then f⁻¹(7) = 3. The inverse reverses the input-output relationship. To find f^{-1}(0), look in the f(x) column for the value 0; you'll see it's paired with x=2 in the table. Choice B correctly finds f⁻¹(0) = 2 by reading from the table properly. One might accidentally pick 0 or a negative, but recall we're reversing: find input for that output— you're making fantastic progress! Table reading strategy for f⁻¹(a): (1) Look in the f(x) column (the outputs) for the value a, (2) When you find a, look at the x-value in that same row, (3) That x-value is f⁻¹(a). Example: table shows x: 1, 2, 3, 4 and f(x): 5, 9, 13, 17. To find f⁻¹(13), scan the f(x) column for 13 (found in row 3), read x from that row (x = 3), so f⁻¹(13) = 3. The swap happens automatically when you read this way!
Question 17
The function f is one-to-one, so it has an inverse. Using the table, find f−1(2).
| x | f(x) |
|---|
| −2 | −4 |
| 0 | −1 |
| 1 | 2 |
| 3 | 5 |
| 6 | 9 |
- 1 (correct answer)
- −1
- 2
- 5
Explanation: This question tests your ability to read values of an inverse function from a table or graph using the fundamental property that inverses swap inputs and outputs. If f has a table or graph showing its (x, y) pairs, then f⁻¹ has the same pairs but swapped: every (x, y) on f becomes (y, x) on f⁻¹. So to find f⁻¹(a), you don't need the inverse's table or graph—just find where y = a in f's representation and read the corresponding x-value. That x is your answer! For example, if f's table shows x = 3 gives y = 7, then f⁻¹(7) = 3. The inverse reverses the input-output relationship. To find f^{-1}(2), look in the f(x) column for the value 2; you'll see it's paired with x=1 in the table. Choice C correctly finds f⁻¹(2) = 1 by reading from the table properly. Some students might mistakenly pick 2 itself or confuse with another row, but always focus on locating the output first and grabbing the input— you're doing great, keep going! Table reading strategy for f⁻¹(a): (1) Look in the f(x) column (the outputs) for the value a, (2) When you find a, look at the x-value in that same row, (3) That x-value is f⁻¹(a). Example: table shows x: 1, 2, 3, 4 and f(x): 5, 9, 13, 17. To find f⁻¹(13), scan the f(x) column for 13 (found in row 3), read x from that row (x = 3), so f⁻¹(13) = 3. The swap happens automatically when you read this way!