document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=120433>Question 120433</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The parabola y=x2-4 intersects the x axis at two points, P and Q. What is the distance from P to Q? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #88289 by </B><A HREF=/tutors/aboutme.mpl?userid=bucky><B>bucky(2189)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=bucky><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=88289\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Given: the parabola<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y+=+x%5E2-4 ALIGN=MIDDLE  ALT=\"y+=+x%5E2-4\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "To find the intersections with the x-axis, set y = 0 because any point on the x-axis has<BR>\n" );
document.write( "zero as its y-value. So the equation to solve then becomes:<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=0+=+x%5E2-4 ALIGN=MIDDLE  ALT=\"0+=+x%5E2-4\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "Solve this by getting rid of the -4 on the right side by adding +4 to both sides. On the right<BR>\n" );
document.write( "side the -4 and the +4 cancel each other when they are added. So when you add +4 to both sides<BR>\n" );
document.write( "the equation becomes:<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=4+=+x%5E2 ALIGN=MIDDLE  ALT=\"4+=+x%5E2\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "Solve for x by taking the square root of both sides to get two answers:<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+sqrt%284%29=2 ALIGN=MIDDLE  ALT=\"x+=+sqrt%284%29=2\"   DISABLED_style= \"max-width:90%; height:auto;\" > and <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+sqrt%284%29+=+-2 ALIGN=MIDDLE  ALT=\"x+=+sqrt%284%29+=+-2\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "So the intersections of the parabola and the x-axis occur on the x-axis at x = -2 and at<BR>\n" );
document.write( "x = +2. These points are P and Q. And, if you subtract them you get:<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=2-%28-2%29+=+2%2B2+=+4 ALIGN=MIDDLE  ALT=\"2-%28-2%29+=+2%2B2+=+4\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "The points P and Q are 4 units apart.<BR>\n" );
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document.write( "You can see this in the graph of the parabola shown below:<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=graph%28300%2C300%2C-5%2C5%2C-5%2C5%2Cx%5E2+-+4%29 ALIGN=MIDDLE  ALT=\"graph%28300%2C300%2C-5%2C5%2C-5%2C5%2Cx%5E2+-+4%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "Hope this helps you to understand the problem. </SPAN>\n" );
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