Question

Write the equation of the circle R that passes through (1, 1) and has a center C(2, 2).

Answer 1

`(x-x_0)^2+(y-y_0)^=r^2 (x-2)^2+(y-2)^=2`Firstly, we need to find out the radius of the circle

and this is accomplished by the distance formula
`r=√((y_2-y_1)^2+(x_2-x_1)^2) \\ r=√((2-1)^2+(2-1)^2) \\ r=√(1+1) \\ r=√(2) hence:\\ \\ r^2=2`

then the equation of the circle is:


`(x-x_0)^2+(y-y_0)^2=r^2\\ \\(x-2)^2+(y-2)^2=2`