Let circle C be the image of x2+y2-2x+4y-4=0 in the line 2x-3y+5=0 and A be the point on C such that OA is parallel to x-axis and A lies on the right hand side of the centre O of C. If B( , ), with <4, lies on C such that the length of the arc AB is (1/6)th of the perimeter of C, then - 3 is equal to
- 4- 3
- 3
- 4
- 3+ 3
Answer
(3) 4
Solution
Given circle: centre (1,-2), r=3; its image in 2x-3y+5=0 has centre (-3,4), same radius.
[figure]
Arc = 16 of the circle AOB=60 ; <4 puts B below OA
B=(-3+3 60 , 4-3 60 )= (- 32, 4- 3 32 )
- 3 =4- 3 32+ 3 32=4
Answer: (3)