document.write( "Question 493151: How do I find a polynomial function with rational coefficients so that P(x)=0 has the given roots: 13i and 5 + 10i.\r
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document.write( "I tried this:
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document.write( "P(x)=(x+13i)(x^2 + 5 + 10) but when I multiply everything out it is Way off from the answer in the back of the book. \n" );
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Algebra.Com's Answer #335308 by scott8148(6628)![]() ![]() You can put this solution on YOUR website! complex roots (those containing i) occur in conjugate pairs (a+bi and a-bi) \n" ); document.write( "___ also; if r is a root, then x-r is a factor\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "so P(x) has four factors ___ (x + 13i)(x - 13i)[x - (5 + 10i)][x - (5 - 10i)]\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "multiplying the factors should give you the right result \n" ); document.write( " |