00:01
In this question, we ask for the standard form for the equation of a circle.
00:05
X minus h quantity squared plus y minus k quantity squared equals r squared that has a diameter with endpoints at negative 1 comma negative 1 and 5 comma negative 3.
00:21
So h and k stand for the center of this circle.
00:27
So my center is at hk.
00:31
How am i going to find my h and my k? well, the center has to be halfway between the endpoints of the diameter.
00:40
So i am going to find the midpoint of the segment connecting and.
00:50
So to get my h, my x -coordinate of the center, we take the average of those x -coordinates.
00:58
So negative 1 plus 5 being divided by 2.
01:03
And to get my k, the y -coordinate of the center, i average the y -coordinates of the endpoints of the diameter.
01:13
So i take negative 1, i add negative 3 to that, that's the same as subtracting 3, over 2.
01:20
I'm getting negative 1 plus 5 is 4 over 2.
01:26
And then negative 1 minus 3 is negative 4 over 2...