If the probability density function of a random variable x is given by
\(f(x)=\left\{ {\begin{array}{*{20}{c}} {\frac{{k{x^2}}}{2}}&{ - 1 \le x \le 1}\\ 0&\rm {elsewhere,} \end{array}} \right.\)
the value of k is ______.
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If the probability density function of a random variable x is given by
\(f(x)=\left\{ {\begin{array}{*{20}{c}} {\frac{{k{x^2}}}{2}}&{ - 1 \le x \le 1}\\ 0&\rm {elsewhere,} \end{array}} \right.\)
the value of k is ______.