The value of \(\sin\left(\frac{3\pi}{2}\right)\) is \(-1\).
This angle corresponds to \(270^\circ\), which is located on the negative y-axis in the unit circle, where the sine function gives the y-coordinate. Since the y-coordinate at this point is \(-1\), we have:
\[ \sin\left(\frac{3\pi}{2}\right) = -1. \]