Published by:
CGP EDU Academic Team
Published on: August 14, 2026
The radius of circle, touching the parabola y 2 = 8x at (2,4) and passing through (0,4), is
A
1 unit
B
2 units
C
units
D
units
Text Solution
Verified by ExpertsThe correct answer is:
C
units
Equation of the tangent at (2,4) on the parabola y 2 = 8x is y (4) = 
y = x + 2
Let equation of circle touching line y = x + 2 at (2,4) is (x - 2) 2 + (y - 4) 2 + 
(x-y + 2) = 0 which passes through (0,4)
4 + 0 + 
(0-4 + 2) 
= 2
Equation of the required circle is x 2 + y 2 -2x – l0y + 24 = 0
The radius of the circle is 
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