Question

If points Q and R reflections of point P (–3, 4) in X and Y axes respectively, what is QR?

Answer 1

We have to find the reflection of (−3, 4) along x-axis and y-axis.

Reflection of any point P (a, b) along x-axis is (a, b) 

So reflection of (−3, 4) along x-axis is Q (-3, - 4) 

Similarly, reflection of any point P (a, b) along y-axis is (-a, b) 

So, reflection of (−3, 4) along y-axis is  R (3, 4) 

Therefore,

`QR = sqrt((3 + 3)^2 + (4 + 4)^2)`

`= sqrt(36 + 64)`

`= sqrt(100)`

`= 10`