Lesson 7.97.9 Small Group · Group 1
Group 1 · Set BSecond form · new problems, same idea
Learning target With my small group, I can reflect points across the x-axis and y-axis on the coordinate plane — one step at a time, with support.
Remember7.9 Small Group · Group 1
Across the y-axis, x changes sign; across the x-axis, y changes sign; the other coordinate always stays the same. A reflection across an axis flips a point. One coordinate changes sign, and the other stays the same.
Words: Reflection (Reflexión)x-axis (Eje x)y-axis (Eje y)Symmetry (Simetría)Integer (Número entero)
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1Complete each step, then write the final answer.
Reflect (−4, 3) across the y-axis. The new point is (?, 3). What is the missing x-coordinate?
Show your workHint Across the y-axis, x changes sign. y stays the same.
Final answer: -
2Complete each step, then write the final answer.
Reflect (−1, 5) across the y-axis. The new point is (?, 5). What is the missing x-coordinate?
Show your workHint Across the y-axis, x changes sign and y stays the same.
Final answer: -
3Complete each step, then write the final answer.
A video game has a mirror on the x-axis. A star is at (2, −7). Its mirror star is the reflection across the x-axis. What is the y-coordinate of the mirror star?
Show your workHint A mirror on the x-axis flips the point up or down. Which coordinate changes?
Final answer: -
4Complete each step, then write the final answer.
Reflect (−3, −4) across the y-axis. Then reflect the new point across the x-axis. Which quadrant is the final point in?
Show your workHint Do one reflection at a time. Write the point after each one.
Final answer:
Explain your thinkingRosa changed the wrong coordinate. How can you tell which coordinate changes when you reflect?
Sentence starter Across the x-axis, the ___ changes because ___. · Rosa should have changed ___.