document.write( "Question 590300: Please Help me.\r
\n" ); document.write( "\n" ); document.write( "write an equation and graph it\r
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\n" ); document.write( "\n" ); document.write( "1.) A quadratic function with x-intercept (3,0)and(-6,0)and y-intercept (0,-5)\r
\n" ); document.write( "\n" ); document.write( "5.) A cubic function with x-intercept (1,0)(-1/2,0)and(1/4,0)and y-intercept(0,2)\r
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Algebra.Com's Answer #375128 by KMST(5328)\"\" \"About 
You can put this solution on YOUR website!
1.)
\n" ); document.write( "A quadratic polynomial with zeros at x=3 and x=-6, must have (x-3) and (x+6) as factors (and no other factor involving x).
\n" ); document.write( "So, it would be
\n" ); document.write( "\"y=K%28x-3%29%28x%2B6%29=K%28x%5E2%2B3x-18%29\" for some non-zero number K.
\n" ); document.write( "For x=0, \"y=-18K=-5\" --> \"K=5%2F18\"
\n" ); document.write( " is your function.
\n" ); document.write( "You know the graph is a prabola, you know the intercepts,and you know that it opens up because the leading coefficient (5/18) is positive.
\n" ); document.write( "The axis of symmetry of the parabola has to be exactly halfway between its zeros, at \"x=%283-6%29%2F2=-3%2F2\"
\n" ); document.write( "The minimum (vertex) of the parabola has \"x=-3%2F2\"
\n" ); document.write( "and
\n" ); document.write( "Graphing parabolas, with all that information is easy.
\n" ); document.write( "\"graph%28300%2C300%2C-9%2C6%2C-10%2C10%2C%285%2F18%29%28x-3%29%28x%2B6%29%29\"
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\n" ); document.write( "2.) For the second function it would be
\n" ); document.write( " \"y=K%28x-1%29%28x%2B1%2F2%29%28x-1%2F4%29\"
\n" ); document.write( "We do not need to do the whole multiplication to figure out that the independent term (you may call it constant) is \"%28-1%29%28-1%2F2%29%2A%281%2F4%29K=%281%2F8%29K\"
\n" ); document.write( "For x=0, \"y=%281%2F8%29K=2\" --> K=16
\n" ); document.write( "The function is \"y=16%28x-1%29%28x%2B1%2F2%29%28x-1%2F4%29\"
\n" ); document.write( "Its zeros are -1/2, 1/4 and 1, and are the points were it changes sign.
\n" ); document.write( "It is negative for \"x%3C-1%2F2\",
\n" ); document.write( "positive for \"-1%2F2%3Cx%3C1%2F4\" (including x=0, where y=2),
\n" ); document.write( "negative for \"1%2F4%3Cx%3C1\",
\n" ); document.write( "and positive for \"x%3E1\"
\n" ); document.write( " GRAPHING:
\n" ); document.write( "Depending on what you are being taught in class is how you would graph the function in problem 2.
\n" ); document.write( "If they are teaching you the use of a graphing calculator or some graphing program, you would use that.
\n" ); document.write( "If your class is calculus, you would find the derivative, and locate maxima and minima.
\n" ); document.write( "Otherwise, you may calculate the value of the function for a few values of x (maybe x=-1, x=1/2, and x=2), plot those points and the intercepts, and sketch a curve that reasonable passes through all those points.
\n" ); document.write( "This website will graph for me.
\n" ); document.write( "\"graph%28300%2C300%2C+-1%2C3%2F2%2C-15%2C20%2C16%28x-1%29%28x%2B1%2F2%29%28x-1%2F4%29%29\"
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