Question 1067737
<pre>
{{{drawing(400,360,-10,10,-9,9,green(line(-7.794228634,4,7.794228634,4),
line(-7.794228634,0,-7.794228634,4), line(7.794228634,0,7.794228634,4)


),
red(arc(0,0,18,-16,0,180)),red(arc(0,0,18.1,-16.1,0,180)),
graph(400,360,-10,10,-9,9,(-8sqrt(81-x^2)/9)*sqrt(sin(9x))/sqrt(sin(9x))) 


 )}}} {{{matrix(8,1,

matrix(1,8,  18m, is, the, length, of, the, major, axis), 
matrix(1,6,  of, the, "ellipse,", so, the, semi-major), 
matrix(1,4,  axis, has, length, b=9m  ), 
matrix(1,7,  8m, is, the,length, of, the, semi-minor),
matrix(1,3, "axis,", so, a=8m),
matrix(1,6,  The, equation, is, x^2/9^2+y^2/8^2=1, or, x^2/81^""+y^2/64^""=1),
matrix(1,5,  Substitute, y=4, get, x= "" +- 9sqrt(3)/2,so),   
matrix(1,6,  the, width, when, y=4, is, 9sqrt(3)m=15.58845727m)
)}}}

Edwin</pre>