Chapter 8: Using the Transform Toolbox 8-7
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Inverse
The
Inverse
tool constructs an inverse point with respect to a circle and a point, according to the
equation
OM
¦
O M' = r
²
where:
M
and
M'
are points that lie
on a ray with endpoint
O.
O
=
center of circle.
M
= selected
point.
M'
= inverse
point.
*
=
radius of selected circle.
As the selected point approaches the center point, the inverse point approaches a point at infinity.
If
M
is defined to be on a line passing through the circle, the locus of
M'
constructs a circle that
passes through the center of the circle.
If the original point lies in the interior of the circle, the inverse point is constructed in the exterior,
and vice versa. The inverse point lies on a ray with the center point as the endpoint.
Creating an inverse point
1.
Select
Inverse
from the
Transform
toolbox.
2.
Create or select a point as the original point.
Select a point.
3.
Select a circle.
Select a circle.
An inverse point is created.
Modifying an inverse point
Move an inverse point by dragging the point or modifying
the circle that defines it. You cannot manipulate an
inverse point directly because it is a dependent point.
This point
This circle
