circle Q (1 Viewer)

[mojako]

A circle just touches the positive x and y axes, and also passes through the point (1,2).
(i) Draw a diagram to represent this information
(ii) Determine the centre and radius of all such circles

For (i), there are 2 possible locations of (1,2) on the circle right??
How do we do (ii)?

 

[shazzam]

A circle just touches the positive x and y axes, and also passes through the point (1,2).
(i) Draw a diagram to represent this information
(ii) Determine the centre and radius of all such circles

For (i), there are 2 possible locations of (1,2) on the circle right??
How do we do (ii)?

Does ii not address the point that more than one circle satisfies the conditions, and thus you can DO ii by giving the radii of these two such circles...

 

[Archman]

well for a circle to be like that, its centre will hafta lie on y=x
if its (a,a), the radius of circle will be a, so u equate that with the distance between centre and (1,2) to find a.

 

[mojako]

oh ok.
thank you.