document.write( "Question 404494: Solve the inequality. Express the solution using interval notation.\r
\n" ); document.write( "\n" ); document.write( "x4 - 32x2 - 144 > 0 \n" ); document.write( "
Algebra.Com's Answer #285862 by lwsshak3(11628)\"\" \"About 
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Solve the inequality. Express the solution using interval notation.
\n" ); document.write( "x4 - 32x2 - 144 > 0
\n" ); document.write( "..
\n" ); document.write( "Factor to find critical points\r
\n" ); document.write( "\n" ); document.write( "x^4-32x^2-144=0
\n" ); document.write( "(x^2-36)(x^2+4)=0
\n" ); document.write( "x^2-36=0
\n" ); document.write( "(x+6)(x-6)=)
\n" ); document.write( "x=-6,x=6
\n" ); document.write( "x^2+4=0
\n" ); document.write( "x=+-sqrt(-4)= +-2i (2imaginary roots)
\n" ); document.write( "If you draw the critical points on the real number line, you will see there three intervals to consider,(-infinity,-6),(-6,6), and (6,infinity). Since f(x) is required to be >0 or positive, only the intervals where f(x)is positive, meet the requirement. You will find that the middle interval is negative and both intervals on either side are positive.\r
\n" ); document.write( "\n" ); document.write( "ans:
\n" ); document.write( "(-infinity,-6)union(6,+infinity)\r
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