BITSAT2011MathematicsCircleActual
If the lines (3 x-4 y+4=0 ) and (6 x-8 y-7=0 ) are tangents to a circle, then the radius of the circle is
Options
- A(3 / 2 )
- B(3 / 4 )
- C(1 / 10 )
- D(1 / 20 )
Correct answer
B. (3 / 4 )
Step-by-step solution
The diameter of the circle is perpendicular distance between the parallel lines (tangents) (3 x-4 y+4=0 ) and (3 x-4 y- 7 2 =0 ) and so it is equal to ( 4 9+16 + 7 / 2 9+16 = 3 2 ). Hence radius is ( 3 4 )