document.write( "Question 1101465: I need to find all real solutions to this equation:\r
\n" ); document.write( "\n" ); document.write( "4x^-4 -16x^-2+4 = 0\r
\n" ); document.write( "\n" ); document.write( "This is how a proceeded:\r
\n" ); document.write( "\n" ); document.write( "1/4x^4 - 1/16x^2 +4 = 0; I figured x cannot equal zero, and the LCD = 16x^4\r
\n" ); document.write( "\n" ); document.write( "I multiplied both sides by the LCD to clear the denominators:
\n" ); document.write( "4 - x^2 + 64x^4 = 0
\n" ); document.write( "or
\n" ); document.write( "64x^4 -x^2 +4 = 0
\n" ); document.write( "I made x^2 = w to get a quadratic equation:
\n" ); document.write( "64w^2 -w +4 = 0\r
\n" ); document.write( "\n" ); 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
\n" ); document.write( "\n" ); document.write( "This can't possibly be right, so I must be doing something wrong. Can you help?
\n" ); document.write( "Thank you
\n" ); document.write( "

Algebra.Com's Answer #716044 by stanbon(75887)\"\" \"About 
You can put this solution on YOUR website!
find all real solutions to this equation:
\n" ); document.write( "4x^-4 -16x^-2+4 = 0
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\n" ); document.write( "Let w = x^-2
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\n" ); document.write( "Substitute to get:
\n" ); document.write( "4w^2 - 16w + 4 = 0
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\n" ); document.write( "Solve for \"w\"::
\n" ); document.write( "4(w^2 - 4w + 1) = 0
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\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..
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
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