[bootlin/training-materials updates] master: Graphics: fix formular for ellipses (62de224b)

[Michael Opdenacker]

Repository : https://github.com/bootlin/training-materials
On branch  : master
Link       : https://github.com/bootlin/training-materials/commit/62de224b83a14f03b8fa492cc7e5261cad9a2299

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commit 62de224b83a14f03b8fa492cc7e5261cad9a2299
Author: Michael Opdenacker <michael.opdenacker at bootlin.com>
Date:   Fri Oct 4 11:23:18 2019 +0200

    Graphics: fix formular for ellipses
    
    - Fixing "a cos()" turned into "acos()"
      I thought it was an "arc cosine"
    
    Signed-off-by: Michael Opdenacker <michael.opdenacker at bootlin.com>


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62de224b83a14f03b8fa492cc7e5261cad9a2299
 slides/graphics-theory/graphics-theory.tex | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/slides/graphics-theory/graphics-theory.tex b/slides/graphics-theory/graphics-theory.tex
index 8da06166..9c2183ba 100644
--- a/slides/graphics-theory/graphics-theory.tex
+++ b/slides/graphics-theory/graphics-theory.tex
@@ -690,8 +690,8 @@ y = y_c + radius \times sin(\phi)
     \end{itemize}
   \item Ellipse: \(\phi \in [0;2\pi]\)
 \begin{gather*}
-x = x_c + a cos(\phi)\\
-y = y_c + b cos(\phi)
+x = x_c + a \times cos(\phi)\\
+y = y_c + b \times cos(\phi)
 \end{gather*}
   \item Many more parametric curves exist:
     \begin{itemize}