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MHT CET202120 Sep 2021Morning ShiftMathematicsCircleActual

If the lines 3 x-4 y+4=0 and 6 x-8 y-7=0 are tangent to circle, then the radius of the circle is

Options

  1. A7 4 units
  2. B3 4 units
  3. C4 3 units
  4. D1 4 units

Correct answer

B. 3 4 units

Step-by-step solution

We have, 3 x-4 y+4=0 and 6 x-8 y-7=0 3 x-4 y- 7 2 =0 Lines (1) and (2) are parallel to one another and these lines are tangents to the circle. Distance between the lines is equal to diameter of circle. D = |4- ( -7 2 ) | (3)^2+(-4)^2 = (4+ 7 2 ) 25 = 15 2(5) = 3 2 radius = 3 4 units

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