what is radical line?

Answer 1

http://mathworld.wolfram.com/RadicalLine.html

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Doug

Answer 2

The radical line, also called the radical axis, is the locus of points of equal circle power with respect to two nonconcentric circles. By the chordal theorem, it is perpendicular to the line of centers (Dörrie 1965).

Let the circles have radii and and their centers be separated by a distance . If the circles intersect in two points, then the radical line is the line passing through the points of intersection. If not, then draw any two circles which cut each original circle twice. Draw lines through each pair of points of intersection of each circle. The line connecting their two points of intersection is then the radical line.

Given two circles with trilinear equations (1)
(2)


their radical line has equation (3)


(Kimberling 1998, p. 224).

The radical line is located at distances (4)
(5)


along the line of centers from and , respectively, where (6)


The radical line of any two polar circles is the altitude from the third vertex.

Answer 3

A line of protesters.

Not really... it's that line that indicates what is intended to be included in a radical sign(√). Like square root.

Answer 4

i suppose that radical line is nothing but radical axis...radical axis is the line perpendicular bisector of the line joining the centres of circles...
it has many applications in the geometry....