document.write( "Question 252215: Find all real values of x for which the functionsare equal. Give your answers to the nearest hundredth.\r
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document.write( "p(x)=x^2-2x+1,Q(x)=-x^3+3x^2-3x+3\r
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document.write( "P(x)=x^4-5x^2+4,Q(x)=2 \n" );
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Algebra.Com's Answer #184075 by drk(1908) ![]() You can put this solution on YOUR website! Let's look at the first equation set. \r \n" ); document.write( "\n" ); document.write( "x^2 -2X+1 = -X^3+3x^2 - 3X + 3 \n" ); document.write( "X^3 -2X^2 + X -2 = 0 \n" ); document.write( "x^2(X-2) + 1(X-2) = 0 \n" ); document.write( "(X^2+1)(X-2) = 0 \n" ); document.write( "So, we set each part = 0. \n" ); document.write( "X^2 + 1 = 0 \n" ); document.write( "X^2 = -1. Here we have either no solution or +-i \n" ); document.write( "X-2 = 0. \n" ); document.write( "X=2. This is the only real solution.\r \n" ); document.write( "\n" ); document.write( "Now, let's look at the second equation set. \n" ); document.write( "X^4 - 5X^2 +4 = 2 \n" ); document.write( "X^4 - 5X^2 +2 = 0 \n" ); document.write( "Let U = X^2. This a \"dummy variable\" substitution. We get \n" ); document.write( "U^2 - 5U +2 = 0. \n" ); document.write( "We apply the quadratic to get \n" ); document.write( "U = (5 +- sqrt(25-8))/2 \n" ); document.write( "U = (5 +- sqrt(17))/2. \n" ); document.write( "We resubstitute X^2 for U and get \n" ); document.write( "X^2 = (5 +- sqrt(17))/2. \n" ); document.write( "X = +-sqrt((5 +-sqrt(17))/2). These are both real solutions. \n" ); document.write( " |