document.write( "Question 82590This question is from textbook
\n" ); document.write( ": For f(x)= 1/x^2-2x-8, find the intervals where f(x)<0 \n" ); document.write( "
Algebra.Com's Answer #59180 by stanbon(75887)\"\" \"About 
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For f(x)= 1/x^2-2x-8, find the intervals where f(x)<0
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\n" ); document.write( "f(x) = 1/[(x-4)(x+2)]
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\n" ); document.write( "Comment: f(x) has vertical asymptotes at x=-2 and x=4
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\n" ); document.write( "Draw a number line and mark appropriate points as x=-2 and as x=4.
\n" ); document.write( "That breaks the line into three intervals. Check a point in each
\n" ); document.write( "interval to see where the solution intervals for your equation lie.
\n" ); document.write( "Check (-inf,-2): pick x=100, then f(-100)=1/(-)(-)>0; no solutions there.
\n" ); document.write( "Check (-2,4); pick x=0, then f(0) = 1/(-)(+)<0; solution here.
\n" ); document.write( "Check (4,inf); pick x=100; then f(100)= 1/(+)(+); no solutions there.
\n" ); document.write( "The solution is all vales of x between x=-2 and x=4 but not including
\n" ); document.write( "x=-2 and x=4.
\n" ); document.write( "Interval notation solution: (-2,4)\r
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
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