The value of $T\left(\frac{1}{2}\right)$ is :
The question asks for the value of $T\left(\frac{1}{2}\right)$. Given the options and the common mathematical context where such questions appear, $T(x)$ typically represents the Gamma function, denoted as $\Gamma(x)$.
The Gamma function $\Gamma(x)$ is a generalization of the factorial function to complex and real numbers. A fundamental property of the Gamma function is its value at $x = \frac{1}{2}$:
$ \Gamma\left(\frac{1}{2}\right) = \sqrt{\pi} $
Assuming $T(x) = \Gamma(x)$, we can directly apply this property:
$ T\left(\frac{1}{2}\right) = \Gamma\left(\frac{1}{2}\right) = \sqrt{\pi} $
Therefore, the value of $T\left(\frac{1}{2}\right)$ is $\sqrt{\pi}$.