Question

Point Q of quadrilateral QRST is (-9,2). What is the image of Q after QRST has been reflected across

Answer 1

Answer:

(-2,9)

(2,-9)

Step-by-step explanation:

The point Q of quadrilateral QRST has coordinate (-9,2).

When this point is reflected across the y-axis , we negate the x-coordinate to obtain $(--9,2)=(9,2)$.

This point is again rotated through an angle of 90 degrees(counterclockwise) about the origin.

The rule for 90 degrees counterclockwise rotation is $(x,y)\to(-y,x)$.

$\implies (9,2)\to(-2,9)$

Therefore the image of Q(-9,2) after a reflection across the y-axis followed by a 90 degrees counterclockwise rotation about the origin is is Q'(-2,9).

However, the rotation could also be clockwise.

The rule for 90 degrees clockwise rotation is $(x,y)\to(y,-x)$.

$\implies (9,2)\to(2,-9)$

The image of Q(-9,2) after a reflection across the y-axis followed by a 90 degrees clockwise rotation about the origin is is Q'(2,-9).

Both answers are there, so you can check them since the question did not specify the direction.