document.write( "Question 224743: Complete each of the following for the function g(x)=-3x^2-6x+1
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\n" ); document.write( "c.Find the y-intercept
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Algebra.Com's Answer #167908 by drj(1380)\"\" \"About 
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Complete each of the following for the function g(x)=-3x^2-6x+1\r
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\n" ); document.write( "\n" ); document.write( "a.Find the vertex of g(x)\r
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\n" ); document.write( "\n" ); document.write( "b.Find the x-intercept \r
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\n" ); document.write( "\n" ); document.write( "c.Find the y-intercept \r
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\n" ); document.write( "\n" ); document.write( "\"g%28x%29=-3x%5E2-6x%2B1\"\r
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\n" ); document.write( "\n" ); document.write( "Step 1. The general formula for a parabola is \"y-b=c%28x-a%29%5E2\" where x=a and y=b is the vertex or at point (a,b). Here, c is a constant.\r
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\n" ); document.write( "\n" ); document.write( "Step 2. Put \"g%28x%29=y=-3x%5E2-6x%2B1\" in standard form by completing the square in x with the following steps.\r
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\n" ); document.write( "\n" ); document.write( "\"y=-3x%5E2-6x%2B1=-3x%5E2-6x-3%2B3%2B1=3%28x%2B1%29%2B4\" where we added zero 0=-3+3 to complete the square\r
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\n" ); document.write( "\n" ); document.write( "Factor out -3 in the first three terms\r
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\n" ); document.write( "\n" ); document.write( "\"y=-3%28x%5E2%2B2x%2B1%29%2B3%2B1=-3%28x%2B1%29%5E2%2B4\"\r
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\n" ); document.write( "\n" ); document.write( "Subtract 4 from both sides of the equation\r
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\n" ); document.write( "\n" ); document.write( "\"y-4=-3%28x%2B1%29%5E2%2B4-4\"\r
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\n" ); document.write( "\n" ); document.write( "\"y-4=-3%28x%2B1%29%5E2\"\r
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\n" ); document.write( "\n" ); document.write( "ANSWER: So the vertex is located at point (-1, 4)\r
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\n" ); document.write( "\n" ); document.write( "Step 3. To find the x-intercept, set g(x)=y=0. We use the quadratic formula given as\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+\" \r
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\n" ); document.write( "\n" ); document.write( "where a=-3, b=-6 and c=1\r
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Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation \"ax%5E2%2Bbx%2Bc=0\" (in our case \"-3x%5E2%2B-6x%2B1+=+0\") has the following solutons:
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\n" ); document.write( " \"x%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca\"
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\n" ); document.write( " For these solutions to exist, the discriminant \"b%5E2-4ac\" should not be a negative number.
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\n" ); document.write( " First, we need to compute the discriminant \"b%5E2-4ac\": \"b%5E2-4ac=%28-6%29%5E2-4%2A-3%2A1=48\".
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\n" ); document.write( " Discriminant d=48 is greater than zero. That means that there are two solutions: \"+x%5B12%5D+=+%28--6%2B-sqrt%28+48+%29%29%2F2%5Ca\".
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\n" ); document.write( " \"x%5B1%5D+=+%28-%28-6%29%2Bsqrt%28+48+%29%29%2F2%5C-3+=+-2.15470053837925\"
\n" ); document.write( " \"x%5B2%5D+=+%28-%28-6%29-sqrt%28+48+%29%29%2F2%5C-3+=+0.154700538379251\"
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\n" ); document.write( " Quadratic expression \"-3x%5E2%2B-6x%2B1\" can be factored:
\n" ); document.write( " \"-3x%5E2%2B-6x%2B1+=+-3%28x--2.15470053837925%29%2A%28x-0.154700538379251%29\"
\n" ); document.write( " Again, the answer is: -2.15470053837925, 0.154700538379251.\n" ); document.write( "Here's your graph:
\n" ); document.write( "\"graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+-3%2Ax%5E2%2B-6%2Ax%2B1+%29\"

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\n" ); document.write( "\n" ); document.write( "Step 4. To find the y-intercept set x=0 in g(x)=y=-3x^2-6x+1 \r
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\n" ); document.write( "\n" ); document.write( "\"g%280%29=y=-3%2A0%5E2-6%2A0%2B1\"\r
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\n" ); document.write( "\n" ); document.write( "or y=1. \r
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\n" ); document.write( "\n" ); document.write( "The y-intercept is at (0,1) which is consistent with the above graph.\r
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\n" ); document.write( "\n" ); document.write( "I hope the above steps and explanation were helpful.\r
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\n" ); document.write( "\n" ); document.write( "For FREE Step-By-Step videos in Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra and for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.\r
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\n" ); document.write( "\n" ); document.write( "And good luck in your studies!\r
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\n" ); document.write( "\n" ); document.write( "Respectfully,
\n" ); document.write( "Dr J\r
\n" ); document.write( "\n" ); document.write( "http://www.FreedomUniversity.TV\r
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