document.write( "Question 190967: This is an update of a previous problem which I copied wrong
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document.write( "I need to find a polynomial of degree 4 with integer coefficients that have roots:-2,5,and 3+2i such that P(3)=-80. I know to use the conjugate of 3+2i which is 3-2i, and I know how to put them in the f(x)=a(x-r1)(x-r2...format, but from there I get tripped up and can't figure out what to do with P(3)=-80. Thanks. \n" );
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Algebra.Com's Answer #143377 by stanbon(75887)![]() ![]() ![]() You can put this solution on YOUR website! This is an update of a previous problem which I copied wrong \n" ); document.write( "I need to find a polynomial of degree 4 with integer coefficients that have roots:-2,5,and 3+2i such that P(3)=-80. I know to use the conjugate of 3+2i which is 3-2i, and I know how to put them in the f(x)=a(x-r1)(x-r2...format, but from there I get tripped up and can't figure out what to do with P(3)=-80. \n" ); document.write( "------------------------------------------- \n" ); document.write( "P(x) = a(x+2)(x-5)(x-(3+2i))(x-(3-2i)) \n" ); document.write( "--- \n" ); document.write( "Use P(3) = -80 to determine the value of \"a\": \n" ); document.write( "---- \n" ); document.write( "P(3) = a(5)(-2)(-2i)(2i) = -80 \n" ); document.write( "a(-10)(4) = -80 \n" ); document.write( "a(-40) = -40 \n" ); document.write( "a = 2 \n" ); document.write( "-------------- \n" ); document.write( "Now you know the equation is:P(x) = 2(x+2)(x-5)(x-(3+2i))(x-(3-2i)) \n" ); document.write( "==================================================================== \n" ); document.write( "Cheers, \n" ); document.write( "Stan H. \n" ); document.write( " \n" ); document.write( " |