document.write( "Question 484241: I'm having trouble with this problem. Thanks for your help.
\n" ); document.write( "Solve. Express x as a logarithm if necessary.
\n" ); document.write( "e^(x)+e^(-x)=4 \n" ); document.write( "

Algebra.Com's Answer #331341 by chessace(471) $\"\"$ $\"About$

You can put this solution on YOUR website!
Let z= $\"e%5Ex\"$
\n" ); document.write( "Note that $\"y%5E%28-a%29\"$ = $\"1%2Fy%5Ea\"$
\n" ); document.write( "So we have z + 1/z = 4
\n" ); document.write( "*z: $\"z%5E2\"$ + 1 = 4z
\n" ); document.write( " $\"z%5E2\"$ - 4z +1 =0
\n" ); document.write( "z = $\"%28-%28-4%29%2B-sqrt%28%28-4%29%5E2-4%281%29%281%29%29%29%2F%282%2A1%29\"$
\n" ); document.write( "z = $\"%284%2B-sqrt%2816-4%29%29%2F2\"$
\n" ); document.write( " $\"sqrt%2812%29\"$ = $\"sqrt%284%2A3%29\"$ = 2 * sqrt(3)
\n" ); document.write( "z = $\"2%2B-sqrt%283%29%29\"$
\n" ); document.write( "Ln(z) = x (natural log base e)
\n" ); document.write( "So x = $\"Ln%282+%2B-+sqrt%283%29%29\"$
\n" ); document.write( " \n" ); document.write( "

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