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Math Help - Inequality using sign chart

  1. #1
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    Question Inequality using sign chart

    Solve the inequality using a sign chart.

    (x^3 - 4x)/(x^2 + 2) ≤ 0.

    I'm not really sure how to start, but I do know how to use a sign chart.
    Any help would be appreciated.
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  2. #2
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    Krizalid's Avatar
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    You mean something like

    \begin{array}{*{20}c}<br />
   {} &\vline &  {( - \infty , - 2)} &\vline &  {( - 2,0)} &\vline &  {(0,2)} &\vline &  {(2,\infty )}  \\<br />
\hline<br />
   x &\vline &   -  &\vline &   -  &\vline &   +  &\vline &   +   \\<br />
\hline<br />
   {x - 2} &\vline &   -  &\vline &   -  &\vline &   -  &\vline &   +   \\<br />
\hline<br />
   {x + 2} &\vline &   -  &\vline &   +  &\vline &   +  &\vline &   +   \\<br /> <br />
 \end{array}

    ?
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  3. #3
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    Quote Originally Posted by Krizalid View Post
    You mean something like

    \begin{array}{*{20}c}<br />
{} &\vline & {( - \infty , - 2)} &\vline & {( - 2,0)} &\vline & {(0,2)} &\vline & {(2,\infty )} \\<br />
\hline<br />
x &\vline & - &\vline & - &\vline & + &\vline & + \\<br />
\hline<br />
{x - 2} &\vline & - &\vline & - &\vline & - &\vline & + \\<br />
\hline<br />
{x + 2} &\vline & - &\vline & + &\vline & + &\vline & + \\<br /> <br />
\end{array}

    ?

    Yes, but I was able to figure it out.
    If at all possible, could you look at my post titled Pre-Calc HW questions?
    I really need help on those.
    Thanks!!
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