NTA Abhyas JEE Main2020MathematicsCirclePractice
The line 2 x - y + 1 = 0 touches a circle at the point 2 , 5 and the centre of the circle lies on x - 2 y = 4 . The diameter (in units) of the circle is
Options
- A6 5
- B10 3
- C4 5
- D10 2
Correct answer
A. 6 5
Step-by-step solution
tan θ = 2 - 1 2 1 + 2 1 2 = 3 4 r 8 2 + 4 2 = tan θ = 3 4 = r 4 5 ⇒ r = 3 5 ⇒ diameter = 6 5 units