document.write( "Question 308536: Hello,
\n" ); document.write( "I am trying to solve quadratic equations by graphing, I have been looking at the example of the book and makes no sence to me.
\n" ); document.write( "the problem is asking me to use a graph to estimate the solutions of the equation, and to check my solutions algebraically.\r
\n" ); document.write( "\n" ); document.write( "\"+-4x%5E2-8x=12+\"
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Algebra.Com's Answer #220610 by stanbon(75887)\"\" \"About 
You can put this solution on YOUR website!
use a graph to estimate the solutions of the equation, and to check my solutions algebraically.\r
\n" ); document.write( "\n" ); document.write( "-4x^2-8x=12
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\n" ); document.write( "Divide thru by -4 to simplify the equation.
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\n" ); document.write( "x^2 + 2x = -3
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\n" ); document.write( "Graph the two equations
\n" ); document.write( "y = x^2+2x
\n" ); document.write( "and
\n" ); document.write( "y = -3
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\n" ); document.write( "\"graph%28400%2C300%2C-10%2C10%2C-10%2C10%2Cx%5E2%2B2x%2C-3%29\"
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\n" ); document.write( "Find the points of intersection of the two graphs.
\n" ); document.write( "Note: The graphs do not intersect; there is no Real
\n" ); document.write( "Number solutions for the problem.
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\n" ); document.write( "Solving analytically:
\n" ); document.write( "x^2 + 2x +3 = 0
\n" ); document.write( "x = [-2 +- sqrt(4 -4*3)]/2
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\n" ); document.write( "x = [-2 +- sqrt(-8)]/2
\n" ); document.write( "x = [-2 +-2isqrt(2)]/2
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\n" ); document.write( "x = [-1 +- isqrt(2)]
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\n" ); document.write( "Note: These solutions are complex numbers.
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
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