The first general circle formula is,(adsbygoogle = window.adsbygoogle || []).push({});

[tex]

(x-a)^2+(y-b)^2=r^2

[/tex]

Where M(a,b) and r:radius.

I understand this well, but when the subject is arcs...

[tex]

(x-a)^2=r^2-(y-b)^2

[/tex]

[tex]

x_\textrm{1,2} =a (+-) \sqrt{r^2-(y-b)^2}

[/tex]

My teacher said that equations for x1 and x2 were half circles at right and left. But how?

And also the same fo y,

[tex]

y_\textrm{1,2}=b(+-)\sqrt{r^2-(x-a)^2}

[/tex]

were the arcs of top half and bottom of the circle. But why?

Any help is appreciated.

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# Analytics of an Arc

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