document.write( "Question 1101465: I need to find all real solutions to this equation:\r
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document.write( "4x^-4 -16x^-2+4 = 0\r
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document.write( "This is how a proceeded:\r
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document.write( "1/4x^4 - 1/16x^2 +4 = 0; I figured x cannot equal zero, and the LCD = 16x^4\r
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document.write( "I multiplied both sides by the LCD to clear the denominators:
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document.write( "4 - x^2 + 64x^4 = 0
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document.write( "or
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document.write( "64x^4 -x^2 +4 = 0
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document.write( "I made x^2 = w to get a quadratic equation:
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document.write( "64w^2 -w +4 = 0\r
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document.write( "I tried factoring this, and I couldn't. Then I figured out that the discriminant is less than zero, which will give me imaginary numbers (b^2 -4ac = 1 -1024 = -1023)\r
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document.write( "This can't possibly be right, so I must be doing something wrong. Can you help?
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document.write( "Thank you \n" );
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Algebra.Com's Answer #716044 by stanbon(75887)![]() ![]() ![]() You can put this solution on YOUR website! find all real solutions to this equation: \n" ); document.write( "4x^-4 -16x^-2+4 = 0 \n" ); document.write( "------ \n" ); document.write( "Let w = x^-2 \n" ); document.write( "----- \n" ); document.write( "Substitute to get: \n" ); document.write( "4w^2 - 16w + 4 = 0 \n" ); document.write( "---------------(---------- \n" ); document.write( "Solve for \"w\":: \n" ); document.write( "4(w^2 - 4w + 1) = 0 \n" ); document.write( "---- \n" ); document.write( "Quadratic Formula:: \n" ); document.write( "w = [4 +- sqrt(16-4*1*1)]/2 \n" ); document.write( "w = [4 +- sqrt(12)]/2 \n" ); document.write( "w = 2 +- 2sqrt(3) \n" ); document.write( "w = -1.4641 or w = 5.4641 \n" ); document.write( "------ \n" ); document.write( "Ans:: x = 0.1830.. or x = -0.6830.. \n" ); document.write( "------------ \n" ); document.write( "Cheers, \n" ); document.write( "Stan H. \n" ); document.write( "----------- \n" ); document.write( " \n" ); document.write( " |