document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=424511>Question 424511</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Ellipsoids (three-dimensional ellipses) are used in health care to avoid surgery in the treatment of kidney stones. An elliptical lithotripter emits underwater ultrahigh-frequency (UHF) shock waves from one focus, with the patient's kidney carefully positioned at the other focus.  The ellipse used has a major axis of 12 ft and a minor axis of 5 ft.  <BR>\n" );
document.write( "	a) How far from the center are the foci?<BR>\n" );
document.write( "	b) How far from the lithotripter is the patient's kidney?<BR>\n" );
document.write( "	c) Write an equation for the ellipse used.\r<BR>\n" );
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document.write( "And if you could show work that would be great so I can check my answers and processes to make sure that I did it right. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #295905 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=295905\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\">  The ellipse used has a major axis of 12 ft and a minor axis of 5 ft. <BR>\n" );
document.write( "a) How far from the center are the foci?<BR>\n" );
document.write( "b) How far from the lithotripter is the patient's kidney?<BR>\n" );
document.write( "c) Write an equation for the ellipse used. <BR>\n" );
document.write( "-----<BR>\n" );
document.write( "a^2 = 12^2 = 144<BR>\n" );
document.write( "b^2 = 5^2 = 25<BR>\n" );
document.write( "----<BR>\n" );
document.write( "a^2 = b^2 + c^2<BR>\n" );
document.write( "c = sqrt(144-25)<BR>\n" );
document.write( "c = sqrt(119)<BR>\n" );
document.write( "---<BR>\n" );
document.write( "Focus distance from center = sqrt(119) ft<BR>\n" );
document.write( "===============<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( "===============<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );