Use this feature to create a conic section using user-defined values for the six coefficients in the following equation, which is the general quadratic representation of a conic:

Ax2 + Bxy + Cy2 + Dx + Ey + F = 0

When using this function, keep the following in mind:

NOTE: If a conic cannot be created, the coefficients define a degenerate conic, or one where the start and end positions are coincident and the conic is not an ellipse, an error message appears. Indicate different start and end positions.

• You must include the start position and the end position of the entity. Unless the conic is an ellipse, you cannot choose coincident start and end positions.

• To define a hyperbola, the branch that is closest to the start and end positions is created.

• You cannot indicate coincident positions.

• You cannot direct the tangent vector that defines the slope of the conic at a selected position toward any of the other positions that you indicated in defining the entity.

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

  Using the Function

  1. Select Conic from 6 Coefficients from the Create>Conic submenu.

  2. Enter values for each of the six coefficients.

  3. Indicate a position for the start point of the conic. If the indicated position is not on the conic, the start position is determined by constructing a line that is perpendicular to the conic and passes through the indicated position. It uses the intersection of the conic and the perpendicular line as the start position.

  4. Indicate a position for the end point of the conic. If the indicated point is not on the conic, the end position is determined in the same way it chose the start position.