# Locus question

• Feb 23rd 2010, 10:33 AM
lebanon
Locus question
(c) is a circle of fixed center o and of radius 3 cm , and (c') of radius 1 cm. Suppose that M varies such that the two circles remain externally tangent .
1) determine the locus of M.
2) Let b be a fixed point of (c) . Determine the locus of N , the translate of M by the translation vector BO.(b to O )(Headbang)(Headbang)
• Feb 23rd 2010, 11:03 AM
tonio
Quote:

Originally Posted by lebanon
(c) is a circle of fixed center o and of radius 3 cm , and (c') of radius 1 cm. Suppose that M varies such that the two circles remain externally tangent .
1) determine the locus of M.
2) Let b be a fixed point of (c) . Determine the locus of N , the translate of M by the translation vector BO.(b to O )(Headbang)(Headbang)

1) What is M, anyway?

2) How M "varies" so as the two circles remain externally tangent??

Tonio
• Feb 23rd 2010, 07:18 PM
lebanon
Quote:

Originally Posted by tonio
1) What is M, anyway?

2) How M "varies" so as the two circles remain externally tangent??

Tonio

M varies on (c") center o radius 4cm
• Feb 23rd 2010, 07:50 PM
lebanon
M varies on (c") center O radius 4cm
• Feb 24th 2010, 03:14 AM
HallsofIvy
Quote:

(c) is a circle of fixed center o and of radius 3 cm , and (c') of radius 1 cm. Suppose that M varies such that the two circles remain externally tangent .
You still have not said what M is! You also do not say what the center of (c') is. Apparently where M is controls the position of the center of (c'). Is it possible that M is the center of (c')?