Difference between revisions of "1993 IMO Problems/Problem 2"
William122 (talk | contribs) (Created page with "Let <math>D</math> be a point inside acute triangle <math>ABC</math> such that <math>\angle ADB = \angle ACB+\frac{\pi}{2}</math> and <math>AC\cdot BD=AD\cdot BC</math>. \rene...") |
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\renewcommand{\theenumi}{\Alph{enumi}} | \renewcommand{\theenumi}{\Alph{enumi}} | ||
\begin{enumerate} | \begin{enumerate} | ||
− | \item Calculate the ratio \frac{AC\cdot CD}{AC\cdot BD} | + | \item Calculate the ratio <math>\frac{AC\cdot CD}{AC\cdot BD}</math> |
\item Prove that the tangents at <math>C</math> to the circumcircles of <math>\triangle ACD</math> and <math>\triangle BCD</math> are perpendicular. | \item Prove that the tangents at <math>C</math> to the circumcircles of <math>\triangle ACD</math> and <math>\triangle BCD</math> are perpendicular. | ||
+ | \end{enumerate} |
Revision as of 10:34, 21 November 2017
Let be a point inside acute triangle such that and . \renewcommand{\theenumi}{\Alph{enumi}} \begin{enumerate} \item Calculate the ratio \item Prove that the tangents at to the circumcircles of and are perpendicular. \end{enumerate}