Question

to find the centre of a circle whose centre is not known​

Answer 1

Answer:

Given the centre is at (α,β)

The equation of circle be,

(x−α)  

2

+(y−β)  

2

=r  

2

 

The circle passes through origin  

∴α  

2

+β  

2

=r  

2

 

Hence the equation of circle becomes

x  

2

+y  

2

−2αx−2βy=0

The equation of tangent at point (x  

1

​  

,y  

1

​  

) for a standard equation of circle x  

2

+y  

2

+2gx+2fy+c=0 is

xx  

1

​  

+yy  

1

​  

+g(x+x  

1

​  

)+f(y+y  

1

​  

)+c=0

gx+fy+c=0

g=−α,f=−β,c=0

∴αx+βy=0.

Answer 2

Answer:

hi

Step-by-step explanation:

use a compass

expand it by its radious

then draw

u will get