Question

Start with Chanel’s sequence. How does a 90-degree counterclockwise rotation about the origin change the coordinates of a shape? **SEE PIC BELOW**

Answer 1

When a shape is rotated, it must be rotated through a point.

• 90 degrees counterclockwise rotation negates the y-coordinates, and then swap the x and y-coordinates
• Chanel is incorrect

The rule of 90 degrees counterclockwise is:

$(x,y) \to (-y,x)$

This means that:

• The y-coordinate is negated
• Then the y and x coordinates are swapped

However, Charlies transformation is incorrect.

• This is so because, the shape was not rotated, but instead it was reflected  across the x-axis.
• Then, the shape was dilated

Using points L and Q

$L=(1,1)$

When L is reflected across the x-axis.

The rule is:

$(x, y) \to (x, -y)$

So, we have:

$(1, 1) \to (1, -1)$

Next, it is dilated by 2.

The rule of this is:

$(x,y) \to k(x,y)$

So, we have:

$(1,1) \to2 \times (1,-1)$

$(1,1) \to (2,-2)$

From the diagram, the coordinate of Q is:

$Q = (2,-2)$

Same as the calculated point

Hence, Chanel is incorrect

Read more about transformation at:

brainly.com/question/11709244

Answer 2

Answer:

So when rotating a 90 degrees counterclockwise rotation about the origin we have to change (x, y) to (-y, x).