Given tha:
$\displaystyle x=4+4\cos \theta$
$\displaystyle y+3=5\sin \theta$
Show that the above equations represents an ellipse.
$\displaystyle \frac {(x-4)^2}{4^2}+\frac {(y+3)^2}{5^2}=1$
Thats clear, but why this method works
all we do is finding $\displaystyle \sin^2 \theta+\cos^2 \theta $ wich is always = 1
and $\displaystyle \sin^2 \theta+\cos^2 \theta =r^2$ in polar coordinates
I think we do not porve it this way !!
what do you say ?