locus- find eqn of circle (1 Viewer)

[izzy_xo]

hey just wondering if anyone could help me with this question:

Find the eqn of the circle that passes through (7,2) (2,-3) and (-4,-1)

many thanks.

 

[hscishard]

A really bad way of doing it is substitue the points into (x-h)^2+(y-k)^2 = r^2
And then simultaneously solve

 

[Affinity]

A really bad way of doing it is substitue the points into (x-h)^2+(y-k)^2 = r^2
And then simultaneously solve

That's probably the best way without resorting to heavy machinery.

alternatively you can find the equation of 2 perpendicular bisectors of the line segments joining 2 points and solving them to get the center.

 

[hscishard]

Ooo nice. Note that that method uses 3unit maths.