The expression "sin(A - B)" represents the sine of the difference between two angles, A and B. It is a fundamental concept in trigonometry, which studies the relationships between angles and sides of triangles. The sine function is important in various fields, including physics, engineering, and computer graphics. To calculate "sin(A - B)", you can use the sine difference identity: sin(A - B) = sin(A)cos(B) - cos(A)sin(B). This formula allows you to find the sine of the difference by using the sine and cosine values of the individual angles, making it easier to solve problems involving angle differences.