Consider a circle which touches the -axis at and cuts off an intercept on the -axis. Then the radius of the circle is equal to :
- (A)9✓ Correct
- (B)
- (C)8
- (D)
Answer: (A)
Solution
Since the circle touches the -axis at , its center is at where is the radius.
The -intercept length is , so half of it is .
Using Pythagoras: .
Therefore, .
The -intercept length is , so half of it is .
Using Pythagoras: .
Therefore, .

JEE Main · 2021 · 27 Jul 2021 · Shift 2 · Single correct option