A continuous random variable \(X\) has a probability density function \(f(x)=3x^2, 0\leq x\leq 1\) then the value of \(a\) such that \(P(X \leq a)=P(X >a)\) is

\(frac{1}{2}\) \(\left(\frac{1}{2}\right)^{\frac{1}{3}}\) \(\left(\frac{1}{2}\right)^{\frac{1}{4}}\) \(\left(\frac{1}{2}\right)^{\frac{1}{5}}\)

\(\left(\frac{1}{2}\right)^{\frac{1}{3}}\)

\(\int_{0}^{a}3x^2 dx=\int_{a}^{1}3x^2 dx\)