What is the distance between the points (-1,-7) and (-1,4)

Hello from MrBillDoesMath!

11

Discussion:

Solution by distance formula:

d = sqrt( (x2-x1)^2 + (y2-y1)^2)

  = sqrt (  (-1 - (-1) )^2 + (4 - (-7))^2 )

  = sqrt (   ( -1 + 1) ^2 + (4+7)^2)

  = sqrt (   0^2           + 11^ 2    )

  = sqrt ( 11^2)

  = 11

Solution by contemplation!

Note the x coordinate of both points is the same (i.e. -1)  This means the line joining the points is vertical and its length is simply the difference of the y coordinates:   4 - (-7) = 4 + 7 = 11

Thank you,

MrB

the reporter's right

step-by-step explanation:

1/4 = .25 / 25%

for the friend request.

when a figure, such as triangle (xyz) is reflected over the line y = x to create x'y'z' the x-coordinates and y-coordinates of the original image (pre-image) will be reversed for the image. (e.g., (x, y) > (y, x)) this means that the pre-image position of the x- and y-coordinates switch places which in turn provides a mirror like image of the original xyz.  

i notice that when i draw a line segment from x to x', that the points are parallel from each other -- they are exactly across from each other and do not intersect with any other points.  

yes, think i would see the same characteristic if you drew the line segment connecting y with the reflecting line and then y' with the reflecting line because of the essence of reflections. because it is a mirror image, each point was effected the same way which leads me to conclude that they same would apply to y and y'.