Question

Given the center of a circle is at (2,-4) and one of the points on the circle is (5,-8), wat is the length of the diameter of the circle?

Answer 1

a.12
b.10
c.6
d.5

Answer 2

Twice the distance between so 10

Answer 3

how did you get that?
I hv the answer key, but hv no idea how to do

Answer 4

Distance between points is sqrt((2-5)^+(-4-(-8)^2) = 5 = radius so diameter is 2r = 10

Answer 5

wat equation is that?

Answer 6

Essentially it's Pythagorus aka the distance formula

sqrt((x-x1)^2 + (y-y1)^2)

This is a standard formula.

Answer 7

ahhh. behold the glory of a true master. thank you!

Answer 8

ur welcome.

Answer 9

does it matter what is x1 or y1?

Answer 10

Either way, the signs disappear in the squaring.

Answer 11

and this equation basically only works in grids? or can it be used for a real life problem?

Answer 12

In real life u will likely measure the distance with something...:-)

Answer 13

oop. so only on grids

Answer 14

Well, the Cartesian Coordinates are what permits the calculation to be made.

Answer 15

Pythagorus works fine in real life if u have a right angle type problem;

But like I said, u are likey to use an instrument, tape measure, laser , whatever...