C4 vectors

for part d, I don't get what it means by b is the image of a after it is reflected.
Thanks

line 2 is the perpendicular bisector of the line segment AB

Is my stretch matching what you are saying ? I can't remember what bisector means ...
Thanks

The distance from A to (-3,3,7) = the distance from (-3,3,7) to B. (assuming (-3,3,7) is your answer to a)

Sketch looks good yea

bisect means to cut in half, so in this context it means to cut the line segment AB in half

But where is b though? I can't visualize where it is positioned at. Opposite A ? The question does not state b is on any line.

Thanks

since line 2 is perpendicular to line 1 and A lies on line 1 then B must also lie on line 1, on the opposite side

its very similar to me asking you to "reflect the point (-3,0) in the y axis"



since the point lies on the x axis and you want to reflect it in the y axis (which are two perpendicular lines) then you know the reflection point must also lie on the x axis, does that make sense? (ignore the red dot the lower right, i didnt mean that whoops)

Are u suggesting this ? thanks