document.write( "Question 625084: If one zero of the function y= x^2 + mx + n is the square of the other, without finding the zeroes, prove that m^3 = n(3m - n - 1).\r
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document.write( "Thanks in advance.\r
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document.write( "P.S: Is there a method of proving without substitution involved? \n" );
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Algebra.Com's Answer #393284 by oscargut(2103) You can put this solution on YOUR website! Nice problem !!\r \n" ); document.write( "\n" ); document.write( "Here is my answer\r \n" ); document.write( "\n" ); document.write( "y= x^2 + mx + n\r \n" ); document.write( "\n" ); document.write( "Zeros are: a and a^2\r \n" ); document.write( "\n" ); document.write( "Sum of the zeros = -m\r \n" ); document.write( "\n" ); document.write( "a+a^2 = -m\r \n" ); document.write( "\n" ); document.write( "a(a+1) = -m (equation 1)\r \n" ); document.write( "\n" ); document.write( "product of the zeros = n\r \n" ); document.write( "\n" ); document.write( "a^3 = n (equation 2)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "From eq 1)and 2)\r \n" ); document.write( "\n" ); document.write( "(-m)^3 = a^3(a+1)^3 = n(a^3+3a^2+3a+1) = n(n-3m+1)\r \n" ); document.write( "\n" ); document.write( "Then: -m^3 = n(n-3m+1)\r \n" ); document.write( "\n" ); document.write( "m^3 = n(3m-n-1)\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "If you have any doubt or if you have more problems my e-mail is: \r \n" ); document.write( "\n" ); document.write( "mthman@gmail.com \n" ); document.write( " \n" ); document.write( " |