document.write( "Question 204837: f(x)= -2x^3-2x find x if f(x) =-49 \n" ); document.write( "
Algebra.Com's Answer #154687 by RAY100(1637)\"\" \"About 
You can put this solution on YOUR website!
With deference to my esteemed college..perhaps we should try
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\n" ); document.write( "f(x) = -2x^3 -2x =-49,,,when x=?
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\n" ); document.write( "or -2x^3 -2x +49 =0,,,,solve for x.
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\n" ); document.write( "In general this is a negative cubic function.
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\n" ); document.write( "On the x-y coordinate system, this drops from top left to bottom right, with 2 (3-1) turns, and normally 3 answers.
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\n" ); document.write( "Normally we would factor the function, to find the zero's.
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\n" ); document.write( "However after much work, we plotted the function and found that two of the zeros are imaginary. The function does drop and does turn twice, but it only crosses the x axis once, hence 2 imaginary Zeros (3-1=2)
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\n" ); document.write( "The x intercept is at about (2.789, 0)
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\n" ); document.write( "checking: substitute in original function
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\n" ); document.write( "-2(2.789)^3 -2(2.789) =49 ,,,,,,ok
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\n" ); document.write( "Have a great weekend\r
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