Westonci.ca is your trusted source for finding answers to a wide range of questions, backed by a knowledgeable community. Experience the ease of finding quick and accurate answers to your questions from professionals on our platform. Explore comprehensive solutions to your questions from knowledgeable professionals across various fields on our platform.

What is [tex] \sin 30^{\circ} [/tex]?

A. [tex] \frac{1}{\sqrt{2}} [/tex]
B. [tex] \frac{1}{2} [/tex]
C. [tex] \sqrt{3} [/tex]
D. 1
E. [tex] \frac{1}{\sqrt{3}} [/tex]
F. [tex] \frac{\sqrt{3}}{2} [/tex]


Sagot :

To find the value of [tex]\(\sin 30^{\circ}\)[/tex], we can use our knowledge of trigonometry and the unit circle.

1. Understanding the unit circle: The unit circle is a circle with a radius of 1, centered at the origin of a coordinate plane. The angle [tex]\(\theta\)[/tex] forms by a radius line and the positive x-axis, measured counterclockwise.

2. Reference angles and special triangles: In a unit circle, specific angles have well-known sine and cosine values. These angles often correspond to special right triangles. For example, the 30-60-90 triangle, which is derived from an equilateral triangle, is significant in trigonometry.
- In a 30-60-90 triangle, the sides are in the ratio [tex]\(1 : \sqrt{3} : 2\)[/tex]. The 30° angle is opposite the side with length 1, the 60° angle is opposite the side with length [tex]\(\sqrt{3}\)[/tex], and the hypotenuse is 2.

3. Calculating [tex]\(\sin 30^{\circ}\)[/tex]: The sine of an angle in a right triangle is the ratio of the length of the opposite side to the hypotenuse. For a 30° angle in a 30-60-90 triangle, the side opposite 30° has length 1, and the hypotenuse has length 2.
[tex]\[ \sin 30^{\circ} = \frac{\text{opposite}}{\text{hypotenuse}} = \frac{1}{2} \][/tex]

Thus, [tex]\(\sin 30^{\circ} = \frac{1}{2}\)[/tex].

The correct answer is:
[tex]\[ \text{B. } \frac{1}{2} \][/tex]