KCET2016MathematicsCircle
If ( x=2+3 ) and ( y=1-3 ) represent a circle then the centre and radius is
Options
- A( (2,1), 9 )
- B( (2,1), 3 )
- C( (1,2), 1 3 )
- D( (-2,-1), 3 )
Correct answer
B. ( (2,1), 3 )
Step-by-step solution
Given that, x=2+3 (1)y=1-3 (2) From Eqs. (1) and (2) , we have x-2 3 = and y-1 -3 = We know that, ² + ² =1 So, ( x-2 3 )²+ ( y-1 -3 )=1 (x-2)² 9 + (y-1)² 9 =1 (x-2)²+(y-1)²=9 So, it is circle centre at point (2,1) and radius is 3 .