document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1206303>Question 1206303</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Which quadratic function in vertex form can be represented by the graph that has the vertex at (-6, 0) and passes through the point (2, 8)?\r<BR>\n" );
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document.write( "A. y = -1/8x^2 - 6\r<BR>\n" );
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document.write( "B. y = 1/8(x + 6)^2\r<BR>\n" );
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document.write( "C. y = 1/8x^2 - 6\r<BR>\n" );
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document.write( "D. y = -1/8(x + 6)^2 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #843646 by </B><A HREF=/tutors/aboutme.mpl?userid=greenestamps><B>greenestamps(13203)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=greenestamps><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/cgi-bin/show-face.mpl?user=greenestamps><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=843646\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <br><BR>\n" );
document.write( "Vertex form is <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y-k=a%28x-h%29%5E2 ALIGN=MIDDLE  ALT=\"y-k=a%28x-h%29%5E2\"   DISABLED_style= \"max-width:90%; height:auto;\" > or <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y=a%28x-h%29%5E2%2Bk ALIGN=MIDDLE  ALT=\"y=a%28x-h%29%5E2%2Bk\"   DISABLED_style= \"max-width:90%; height:auto;\" ><br><BR>\n" );
document.write( "All the answer choices are in the second form.  So with vertex (-6,0), the correct answer choice has to be in the form <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y=a%28x%2B6%29%5E2%2B0 ALIGN=MIDDLE  ALT=\"y=a%28x%2B6%29%5E2%2B0\"   DISABLED_style= \"max-width:90%; height:auto;\" >, or <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y=a%28x%2B6%29%5E2 ALIGN=MIDDLE  ALT=\"y=a%28x%2B6%29%5E2\"   DISABLED_style= \"max-width:90%; height:auto;\" >.<br><BR>\n" );
document.write( "Answer choices B and D are both in that form.  In answer choice B, a is 1/8; in answer choice D, a is -1/8.  Since the vertex is at (-6,0) and the graph passes through (2,8), we know that the parabola opens upward, which means a is positive, so answer choice B is correct.<br><BR>\n" );
document.write( "More formally, we can substitute x=2 in answer choices B and D to see which gives us the correct value of 8 for y.  With answer choice B, x=2 gives us y=8, which is correct; with answer choice D, x=2 gives us y=-8, which is not.  So again answer choice B is correct.<br><BR>\n" );
document.write( "ANSWER: B<br><BR>\n" );
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