Question

Noor draws PQR in the coordinate plane as shown. Then she reflects PQR across the y-axis to form P'Q'R'. Doug incorrectly says the coordinates of Q' are (-3,2). What is the correct answer? How might Doug have gotten his answer?

Answer 1

1) Let's pick the coordinates of PQR

P (-5,-3) Q ( -3,-2) R( -2,-5)

2) Since a reflection across the y-axis has the following rule

Pre Image Image

(x,y) ---->(-x,y)

3) Then Q' is going to be:

Q Q'

(-3,-2) ---->(3,-2)

Doug might have calculated over the x-axis.