document.write( "Question 726920: x4 + 3x2 = -1 solve fro x \n" ); document.write( "

Algebra.Com's Answer #444895 by tanjo3(60) $\"\"$ $\"About$

You can put this solution on YOUR website!
$\"x%5E4+%2B+3x%5E2+=+-1\"$
\n" ); document.write( " $\"x%5E4+%2B+3x%5E2+%2B+1+=+0\"$ \r
\n" ); document.write( "\n" ); document.write( "Let u be x^2.
\n" ); document.write( " $\"u%5E2+%2B+3u+%2B+1+=+0\"$ \r
\n" ); document.write( "\n" ); document.write( "Using the quadratic formula:
\n" ); document.write( " $\"u+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+\"$
\n" ); document.write( " $\"u+=+%28-3+%2B-+sqrt%28+3%5E2-4%2A1%2A1+%29%29%2F%282%2A1%29+\"$
\n" ); document.write( " $\"u+=+%28-3+%2B-+sqrt%28+5+%29%29%2F2+\"$
\n" ); document.write( " $\"u+=+%28-3+%2B+sqrt%28+5+%29%29%2F2+\"$ , $\"u+=+%28-3+-+sqrt%28+5+%29%29%2F2+\"$ \r
\n" ); document.write( "\n" ); document.write( "Substitute back u=x^2.
\n" ); document.write( " $\"x%5E2+=+%28-3+%2B+sqrt%28+5+%29%29%2F2+\"$ , $\"x%5E2+=+%28-3+-+sqrt%28+5+%29%29%2F2+\"$
\n" ); document.write( " $\"x+=+%2B+sqrt%28%28-3+%2B+sqrt%28+5+%29%29%2F2%29+\"$ , $\"x+=+-+sqrt%28%28-3+%2B+sqrt%28+5+%29%29%2F2%29+\"$ , $\"x+=+%2B+sqrt%28%28-3+-+sqrt%28+5+%29%29%2F2+%29\"$ , $\"x+=+-+sqrt%28%28-3+-+sqrt%28+5+%29%29%2F2+%29\"$ \n" ); document.write( "

\n" );