00:01
Okay, here i want to work out the center and radius of this circle.
00:06
Well, the circle formula in general is x minus a squared plus y minus b squared equals r squared.
00:17
That's called standard form.
00:20
And this means ab is your center and r is your radius.
00:30
So here then what we have, the a i can see is minus two thirds.
00:38
So my center here is going to be minus two thirds and b is one half.
00:52
So negative two thirds and one half is my circle center.
00:57
And the radius i can see is the square root of eight over nine.
01:06
In the words, this here is r squared.
01:08
And that i can write as root 8 over 3 or as 2 root 2 over 3.
01:20
So there is my circle center and there is my radius 2 root 2 over 3 or root 8 over 3 would be fine.
01:34
Now then i want to draw this circle.
01:38
So you have the axes x and y and center first.
01:44
Minus two thirds and one half...