Final answer:
Using the reference angle concept, sin(31π/36) can be written as sin(5π/36), which is the positive acute reference angle in the second quadrant.
Step-by-step explanation:
To find the sine of π - θ, we use the fact that sin(π - θ) = sin θ. Since the reference angle for π - θ lies in the second quadrant, where sine is positive, we can directly use the reference angle to find the equivalent sine expression.
For sin(31π/36), we subtract this from π to find its reference angle:
π - 31π/36 = 36π/36 - 31π/36 = 5π/36
Therefore, sin(31π/36) is equivalent to sin(5π/36), as this positive acute angle is the reference angle for 31π/36.