document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=728278>Question 728278</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Pete sells 10 inch pizzas for $4.30, 12-inch for $5.88, and 14-inch pizzas for $7.78. Assume that the price is a quadratic function of the diameter. \r<BR>\n" );
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document.write( "a) write the particular equation expressing price in terms of diameter.\r<BR>\n" );
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document.write( "b) predict the price of 5-inch mini pizza\r<BR>\n" );
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document.write( "c)If a pizza sells for $20.00 what would expect its diameter to be? (Round to nearest 10th)\r<BR>\n" );
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document.write( "d)What is the significance of the fact that the price intercept is greater than zero? (suggest what it might represent)  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #445366 by </B><A HREF=/tutors/aboutme.mpl?userid=josgarithmetic><B>josgarithmetic(39620)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=josgarithmetic><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=445366\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Writing three quadratic equations using the data and using the general form quadratic coefficients a, b, c, as the variables, you can find that :<BR>\n" );
document.write( "a=0.04<BR>\n" );
document.write( "b=-0.09<BR>\n" );
document.write( "c=1.2\r<BR>\n" );
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document.write( "You can use the matrix tool on the Purdue university site (easy to find using a google web search) for help in finding the coefficients.  The general form function, if quadratic would be <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y=0.04x%5E2-0.09x%2B1.2 ALIGN=MIDDLE  ALT=\"y=0.04x%5E2-0.09x%2B1.2\"   DISABLED_style= \"max-width:90%; height:auto;\" >.\r<BR>\n" );
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document.write( "You can Complete the square using the term (9/8)^2, and you can obtain standard form for the function as <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight%28y=0.04%28x-9%2F8%29%5E2%2B1.15%29 ALIGN=MIDDLE  ALT=\"highlight%28y=0.04%28x-9%2F8%29%5E2%2B1.15%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >.  That last constant, 1.15 is approximate, good to three significant figures. \r<BR>\n" );
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document.write( "The vertex would be x=9/8, and y=1.15.  That is <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1%261%2F8 ALIGN=MIDDLE  ALT=\"1%261%2F8\"   DISABLED_style= \"max-width:90%; height:auto;\" > inch diameter pizza for $1.15.  That sort of pizza is probably not practical; but anyway, the minimum being the vertex is ABOVE the horizontal axis, so the function has NO REAL ZEROS.  \r<BR>\n" );
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document.write( "Using this same equation or function, either <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight%28y=0.04%28x-9%2F8%29%5E2%2B1.15%29 ALIGN=MIDDLE  ALT=\"highlight%28y=0.04%28x-9%2F8%29%5E2%2B1.15%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > or <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight%28y=0.04x%5E2-0.09x%2B1.2%29 ALIGN=MIDDLE  ALT=\"highlight%28y=0.04x%5E2-0.09x%2B1.2%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >, just substitute x=5 and evaluate y, to see the price for the 5 inch diameter pizza.  \r<BR>\n" );
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document.write( "If you want x for y=20, the $20 pizza, you might try taking the standard form of the function you found, and then solve this for x.   </SPAN>\n" );
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