Sinθ is a sine function in trigonometric function, which is used to describe the properties of an angle in a right triangle. Sin 15 represents the sine value with the angle of 15 in a right triangle.

The formula of sinθ is: sinθ = hypotenuse/hypotenuse. In a right triangle, if the hypotenuse is C, the opposite side is A and the adjacent side is B, then θ is the included angle between the hypotenuse and the right side.

Sin 15 is calculated as follows: sin 15 = hypotenuse/hypotenuse. In a right triangle, the length of the hypotenuse is root number 3, and the length of the opposite side is half of the hypotenuse, that is, √3/2. Therefore, sin 15 can be expressed as: sin 15 = √3/2/√3/√ 3. Because √3/√3 = 1, sin15 =1√ 3 = 0.2519045.

Mathematical Significance and Application of Sine

The mathematical significance of sine is mainly reflected in the following aspects:

1, geometric meaning: sine is the ratio of the opposite side to the hypotenuse of a right triangle.

2. Mathematical significance: Sinusoidal function is a periodic function with a period of 2π, and its value range is [- 1, 1].

3. Physical meaning: Sinusoidal function can be used to describe physical phenomena such as vibration and fluctuation.

Sine has a wide range of applications in mathematics, such as:

1. In a triangle, the sine theorem can be used to find the unknown side or angle of the triangle.

2. In analytic geometry, sine function can be used to find the image of curve.

3. In physics, sine function can be used to describe physical phenomena such as vibration and fluctuation.