Composition of Transformations Math Example 1

Follow the full solution, then compare it with the other examples linked below.

Example 1

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Point P(3,1)P(3, 1) is first reflected over the xx-axis, then translated by vector โŸจโˆ’2,4โŸฉ\langle -2, 4 \rangle. Find the final image.

Solution

  1. 1
    Step 1 โ€” Reflect over the xx-axis: (x,y)โ†’(x,โˆ’y)(x, y) \to (x, -y), so P(3,1)โ†’Pโ€ฒ(3,โˆ’1)P(3,1) \to P'(3,-1).
  2. 2
    Step 2 โ€” Translate by โŸจโˆ’2,4โŸฉ\langle -2, 4 \rangle: add โˆ’2-2 to xx and 44 to yy: Pโ€ฒ(3,โˆ’1)โ†’Pโ€ฒโ€ฒ(3โˆ’2,โ€‰โˆ’1+4)=Pโ€ฒโ€ฒ(1,3)P'(3,-1) \to P''(3-2,\,-1+4) = P''(1, 3).
  3. 3
    The final image is Pโ€ฒโ€ฒ(1,3)P''(1, 3).

Answer

Pโ€ฒโ€ฒ=(1,3)P'' = (1, 3)
In a composition of transformations, each transformation is applied in sequence to the result of the previous one. Order matters: reflecting first then translating gives a different result than translating first.

About Composition of Transformations

Composition of transformations applies two or more transformations in sequence to a figure, where the output of one transformation becomes the input of the next. The order matters because transformation composition is generally not commutative.

Learn more about Composition of Transformations โ†’

More Composition of Transformations Examples