Problem Analysis and Solution
The provided worksheet focuses on
rotations and
dilations in the coordinate plane. Let's solve each problem step by step.
---
####
Question 1: What is the rule for rotating a figure 90 degrees counterclockwise?
-
Rotation Rule: When a point \((x, y)\) is rotated 90 degrees counterclockwise about the origin, the new coordinates become \((-y, x)\).
-
Explanation:
- The \(x\)-coordinate becomes the negative of the original \(y\)-coordinate.
- The \(y\)-coordinate becomes the original \(x\)-coordinate.
-
Correct Answer:
B. \((-y, x)\)
---
####
Question 2: What is the rule for rotating a figure 180 degrees?
-
Rotation Rule: When a point \((x, y)\) is rotated 180 degrees about the origin, the new coordinates become \((-x, -y)\).
-
Explanation:
- Both the \(x\)-coordinate and the \(y\)-coordinate are negated.
-
Correct Answer:
C. \((-x, -y)\)
---
####
Question 3: Rotate the point \((5, 5)\) around the origin 180 degrees. State the image of the point.
-
Given Point: \((5, 5)\)
-
Rotation Rule for 180 Degrees: \((x, y) \rightarrow (-x, -y)\)
-
Application:
- Original coordinates: \((5, 5)\)
- New coordinates: \((-5, -5)\)
-
Correct Answer:
D. \((-5, -5)\)
---
####
Question 4: What is the rule for rotating a figure 270 degrees counterclockwise?
-
Rotation Rule: When a point \((x, y)\) is rotated 270 degrees counterclockwise about the origin, the new coordinates become \((y, -x)\).
-
Explanation:
- The \(x\)-coordinate becomes the original \(y\)-coordinate.
- The \(y\)-coordinate becomes the negative of the original \(x\)-coordinate.
-
Correct Answer:
C. \((y, -x)\)
---
####
Question 5: If you were to rotate ABCD 180° about the origin, what would the coordinate of \(A'\) be?
-
Given Figure: The figure shows a rectangle \(ABCD\) with vertex \(A\) at \((3, 5)\).
-
Rotation Rule for 180 Degrees: \((x, y) \rightarrow (-x, -y)\)
-
Application:
- Original coordinates of \(A\): \((3, 5)\)
- New coordinates of \(A'\): \((-3, -5)\)
-
Correct Answer:
A. \((-3, -5)\)
---
####
Question 6: State the coordinate of the image of the given point \(B(-10, -6)\) under a dilation with center at the origin and the given scale factor \(k = \frac{1}{2}\).
-
Given Point: \(B(-10, -6)\)
-
Dilation Rule: For a dilation with center at the origin and scale factor \(k\), the new coordinates are \((kx, ky)\).
-
Scale Factor: \(k = \frac{1}{2}\)
-
Application:
- Original coordinates: \((-10, -6)\)
- New coordinates: \(\left(\frac{1}{2} \cdot (-10), \frac{1}{2} \cdot (-6)\right) = (-5, -3)\)
-
Correct Answer: \((-5, -3)\)
---
Final Answers:
1.
B. \((-y, x)\)
2.
C. \((-x, -y)\)
3.
D. \((-5, -5)\)
4.
C. \((y, -x)\)
5.
A. \((-3, -5)\)
6.
\((-5, -3)\)
Boxed Final Answer:
\[
\boxed{B, C, D, C, A, (-5, -3)}
\]
Parent Tip: Review the logic above to help your child master the concept of rotation math worksheet.