Question bank/JEE Main/Mathematics
JEE MainMathematicsToughCircles
The center of set of circles, each of radius 3, lies on the
circles x^2 + y^2 = 25. The locus of any point in the set is
Show answer and solution
Let (h, k) be any point in the set, then equation of circle is
(x - h)^2 + (y - k)^2 = 9
But (h, k) lie on x^2 + y^2 = 25 then h^2 + k^2 = 25
2 ≤ distance between the centres of two circles ≤ 8
Locus of (h, k) is (4 ≤ x^2 + y^2 ≤ 64)
(x - h)^2 + (y - k)^2 = 9
But (h, k) lie on x^2 + y^2 = 25 then h^2 + k^2 = 25
2 ≤ distance between the centres of two circles ≤ 8
Locus of (h, k) is (4 ≤ x^2 + y^2 ≤ 64)
Source: Grass-G / M-23 Mathematics Paper 31 Dec FST.docx
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