Respuesta :
Distance between two points is 7
Explanation:
This is a question based on reflection of point w.r.t line. During reflection we can see the mirror image with t-shirt print inverted.But the distance from mirror remains same.
Assume a point (x,y), and it reflect in x-axis, then x-axis serves as the mirror, and the new point is (x,-y), because the distance from the mirror remains same. If the reflection of the point is (x,y) in y-axis, then y-axis serves as the mirror, and the new point is (-x,y). And if you reflect (x,y) in y=x line, then new point will be (y,x).
So considering the above question, if new point is (5, -3.5), then the original point must be (5, 3.5)
Distance between two points [tex]P(X_1, Y_1)[/tex] and [tex]Q(X_2, Y_2)[/tex]is given by:
d(P, Q) = [tex]\sqrt{ (X_2-X_1)^{2} + (Y_2-Y_1)^{2}}[/tex]
[tex]Y_2-Y_2 = (3.5) - (-3.5) = 3.5+3.5 = 7\\ \\X_2-X_1 = 5 - 5 = 0[/tex]
[tex]So \sqrt {(Y_2-Y_1)^{2} + (X_2-X_1)^{2}} = \sqrt { 7^{2} + 0^{2}} = \sqrt { 14+0} = \sqrt {14} = 7[/tex]
So distance = 7
