Which of the following is a correct expression for the sine function in trigonometry?

The sine function in trigonometry is defined as the ratio of the length of the opposite side to the length of the hypotenuse in a right-angled triangle. This relationship can be represented by the expression Sin = O/H, where "O" stands for the length of the opposite side and "H" stands for the length of the hypotenuse.

When considering the context of right-angled triangles, the definition of sine is essential in finding the value of angles or lengths of sides. The opposite side is the side opposite to the angle of interest, and the hypotenuse is always the longest side of the triangle, opposite the right angle.

The expression provided aligns perfectly with the foundational understanding of sine in trigonometry, making it the correct answer.

The wrong answers relate to the definitions of other trigonometric functions. For example, Sin = A/H would not be accurate as "A" typically represents the adjacent side, not the opposite side. Similarly, Sin = O/A incorrectly uses "A" instead of "H" for the hypotenuse, and Sin = H/A is entirely inaccurate since it misrepresents the definition of sine by relating the hypotenuse to the opposite side. Understanding these essential definitions is