ISSN : 1226-0657
In this paper we characterize the isogonal and isotomic conjugates of conic. Every conic can be expressed by a quadratic rational B<TEX>$\acute{e}$</TEX>zier curve having control polygon <TEX>$b_0b_1b_2$</TEX> with weight w > 0. We show that the isotomic conjugate of parabola and hyperbola with respect to <TEX>${\Delta}b_0b_1b_2$</TEX> is ellipse, and that the isotomic conjugate of ellipse with the weight <TEX>$w={\frac{1}{2}}$</TEX> is identical. We also find all cases of the isogonal conjugate of conic with respect to <TEX>${\Delta}b_0b_1b_2$</TEX>. Our characterizations are derived easily due to the expression of conic by the quadratic rational B<TEX>$\acute{e}$</TEX>ezier curve in standard form.
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