Combining Transformations
A free Precalculus lesson from the “Transformations and Combinations of Functions” unit, with a worked example and practice problems including step-by-step solutions.
A transformed function is easier to read when shifts, stretches, and reflections are separated before graphing. This lesson is part of Precalculus: Advanced Functions, so the emphasis is on interpreting behavior, choosing the right representation, and explaining the result clearly rather than memorizing isolated algebra moves.
What you'll learn
- Apply multiple transformations in a sensible order
- Use combining transformations in symbolic and graph-based problems
- Check common mistakes before finalizing an answer
Worked example
Problem. Read every transformation in y = 3f(x - 2) + 3.
- Worked Example: First identify exactly what the question is asking: Read every transformation in y = 3f(x - 2) + 3.
- Use inverse operations to isolate the unknown, and keep both sides balanced at every step.
- x - 2 inside shifts right 2.
- The 3 outside stretches vertically by 3.
- + 3 outside shifts up 3.
- Verify the selected choice by checking that it satisfies the original prompt and that the other choices fail the same test.
Answer: right 2, stretch by 3, up 3
Practice problems
1. Read every transformation in y = 3f(x - 2) + 3.
Choices: right 2, stretch by 3, up 3 · left 2, stretch by 3, up 3 · right 2, shrink by 3, down 3 · right 2, stretch by 3, down 3
Show solution
- Warm-up: First identify exactly what the question is asking: Read every transformation in y = 3f(x - 2) + 3.
- Use inverse operations to isolate the unknown, and keep both sides balanced at every step.
- x - 2 inside shifts right 2.
- The 3 outside stretches vertically by 3.
- + 3 outside shifts up 3.
- Verify the selected choice by checking that it satisfies the original prompt and that the other choices fail the same test.
Answer: right 2, stretch by 3, up 3
2. Read every transformation in y = -4f(x - 3) + 4.
Choices: right 3, stretch by 4, reflect over the x-axis, up 4 · right 3, stretch by 4, up 4 · left 3, reflect over the y-axis, up 4 · right 3, reflect over the x-axis, down 4
Show solution
- Warm-up: First identify exactly what the question is asking: Read every transformation in y = -4f(x - 3) + 4.
- For signed numbers, track both distance from zero and direction so the sign of the answer makes sense.
- x - 3 shifts right 3.
- The -4 outside both reflects over the x-axis and stretches by 4.
- + 4 shifts up 4.
- Verify the selected choice by checking that it satisfies the original prompt and that the other choices fail the same test.
Answer: right 3, stretch by 4, reflect over the x-axis, up 4
3. When several transformations appear at once, a useful first move is to:
Choices: separate the inside changes from the outside changes · multiply every constant together first · ignore the horizontal change · graph only the final answer
Show solution
- Inside changes (with x) act horizontally.
- Outside changes (the a and k) act vertically.
- Separating them keeps horizontal and vertical moves from mixing.
Answer: separate the inside changes from the outside changes
4. The point (2, 2) lies on y = f(x). Find the x-coordinate of its image on y = 3f(x - 1) + 6.
Show solution
- Core Practice: First identify exactly what the question is asking: The point (2, 2) lies on y = f(x). Find the x-coordinate of its image on y = 3f(x - 1) + 6.
- For function notation, treat the value inside parentheses as the input and carefully substitute it into the rule.
- Only the inside x - 1 moves the input.
- A point at x = 2 shifts to x = 2 + 1.
- So the new x-coordinate is 3.
- Check the result by substituting or estimating: the response should match 3 and make sense in the original problem.
Answer: 3
5. The point (3, 3) lies on y = f(x). Find the y-coordinate of its image on y = 4f(x - 2) + 2.
Show solution
- Core Practice: First identify exactly what the question is asking: The point (3, 3) lies on y = f(x). Find the y-coordinate of its image on y = 4f(x - 2) + 2.
- For function notation, treat the value inside parentheses as the input and carefully substitute it into the rule.
- The outside acts on the output: y becomes 4y + 2.
- 4(3) + 2 = 12 + 2.
- So the new y-coordinate is 14.
- Check the result by substituting or estimating: the response should match 14 and make sense in the original problem.
Answer: 14
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