Final answer:
To evaluate sin (π/2), the sine value at an angle of π/2 is 1.
Step-by-step explanation:
To evaluate sin (π/2), we can use the unit circle to find the sine value at an angle of π/2. In the unit circle, the x-coordinate at this angle is 0 and the y-coordinate is 1. Therefore, sin (π/2) = 1.