What is sin inverse of sin of 3 pi over 8?

The sin inverse of sin(3π/8) is 3π/8 because the angle 3π/8 lies within the range of the arcsine function, which is [-π/2, π/2]. Since it falls within this range, the sin inverse function returns the original angle. Therefore, sin⁻¹(sin(3π/8)) = 3π/8.