6 COEFF (six coefficients) allows you to create a conic
section by entering values for the six coefficients of the
following equation, which is the general quadratic
representation of a conic:

       A*x^2 + B*x*y + C*y^2 + D*x + E*y + F = 0

Your definition of the desired conic must include the 
start point and the endpoint of the entity.

In response to the appropriate prompts, enter values for
each of the six coefficients and press <Enter>, or accept
any of the default values by pressing <Enter>.

Indicate a position for the start point of the conic, 
using a Position Menu option.

If the indicated point is not on the conic, the program
determines the start point by constructing a line that 
is perpendicular to the conic and passes through the 
indicated point. The intersection of the conic and the 
perpendicular line is used as the start point.

Indicate a position for the endpoint of the conic, using a
Position Menu option. If the indicated point is not on 
the conic, the program determines the endpoint in the 
manner described for the start point.

If a conic cannot be created (e.g., the coefficients 
define a degenerate conic, the start and endpoints are 
coincident and the conic is not an ellipse), an error 
message is displayed. Press <Enter> and indicate different
start and endpoints.

The conic is created in the current construction view, at
the current depth.

If the start and endpoints are coincident and the
coefficients define an ellipse, the entire ellipse is
created.
