document.write( "Question 224798: find the equation whose roots are 5+3i \n" ); document.write( "
Algebra.Com's Answer #167885 by drj(1380)\"\" \"About 
You can put this solution on YOUR website!
Find the equation whose roots are 5+3i.\r
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\n" ); document.write( "\n" ); document.write( "Step 1. We note that \"i=sqrt%28-1%29\" and \"i%5E2=sqrt%28-1%29%2Asqrt%28-1%29=-1\"\r
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\n" ); document.write( "\n" ); document.write( "Step 2. Roots are \"x=5%2B3i\" and \"x=5-3i\" since complex roots appear in pairs\r
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\n" ); document.write( "\n" ); document.write( "Step 3. Then we have the following\r
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\n" ); document.write( "\n" ); document.write( "For x=5+3i, subtract 5+3i from both sides of the equation.\r
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\n" ); document.write( "\n" ); document.write( "\"x-%285%2B3i%29=5%2B3i-%285%2B3i%29=0\"\r
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\n" ); document.write( "\n" ); document.write( "\"x-%285%2B3i%29=0\" Equation A\r
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\n" ); document.write( "\n" ); document.write( "for x=5-3i, subtract 5-3ik from both sides of the equation\r
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\n" ); document.write( "\n" ); document.write( "\"x-%285-3i%29=5-3i-%285-3i%29=0\"\r
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\n" ); document.write( "\n" ); document.write( "\"x-%285-3i%29=0\" Equation B\r
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\n" ); document.write( "\n" ); document.write( "Step 4. Multiply Equations A and B\r
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\n" ); document.write( "\n" ); document.write( "\"%28x-%285%2B3i%29%29%2A%28x-%285-3i%29%29=0\"\r
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\n" ); document.write( "\n" ); document.write( "Multiply out the terms using the FOIL method:\r
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\n" ); document.write( "\n" ); document.write( "\"%28x-%285%2B3i%29%29%2A%28x-%285-3i%29%29=x%5E2-10x%2B34%29\"\r
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\n" ); document.write( "\n" ); document.write( "Step 4. ANSWER: The solution is \"x%5E2-10x%2B34%29\"\r
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\n" ); document.write( "\n" ); document.write( "Let's check with 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=1, b=-10 and c=34.\r
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Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation \"ax%5E2%2Bbx%2Bc=0\" (in our case \"1x%5E2%2B-10x%2B34+=+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=%28-10%29%5E2-4%2A1%2A34=-36\".
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\n" ); document.write( " The discriminant -36 is less than zero. That means that there are no solutions among real numbers.

\n" ); document.write( " If you are a student of advanced school algebra and are aware about imaginary numbers, read on.

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\n" ); document.write( " In the field of imaginary numbers, the square root of -36 is + or - \"sqrt%28+36%29+=+6\".
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\n" ); document.write( " The solution is \"x%5B12%5D+=+%28--10%2B-+i%2Asqrt%28+-36+%29%29%2F2%5C1+=++%28--10%2B-+i%2A6%29%2F2%5C1+\"
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\n" ); document.write( " Here's your graph:
\n" ); document.write( "\"graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+1%2Ax%5E2%2B-10%2Ax%2B34+%29\"

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\n" ); document.write( "\n" ); document.write( "Ignoring the graph below, we have complex roots to this quadratic to be the same ones as given in the problem.\r
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\n" ); document.write( "\n" ); document.write( "I hope the above steps 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( "Good luck in your studies!\r
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\n" ); document.write( "\n" ); document.write( "Respectfully,
\n" ); document.write( "Dr J\r
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