Recognizing 60∘ as a special angle: Recognize that 60∘ is a special angle in trigonometry, and we can use the unit circle or special triangles to find the cosine of this angle.
Using special triangles to find cosine of 60 degrees: Recall that the cosine of 60 degrees corresponds to the adjacent side over the hypotenuse in a 30-60-90 special right triangle, where the sides are in the ratio 1:3:2.
Calculating cosine of 60 degrees using special triangle ratio: In such a triangle, the cosine of 60 degrees is equal to the length of the shorter leg (adjacent to the 60-degree angle) over the hypotenuse. The shorter leg has a length of 1, and the hypotenuse has a length of 2.
Calculating cosine of 60 degrees using special triangle ratio: In such a triangle, the cosine of 60 degrees is equal to the length of the shorter leg (adjacent to the 60-degree angle) over the hypotenuse. The shorter leg has a length of 1, and the hypotenuse has a length of 2.Calculate the value of cos(60∘) using the ratio from the special triangle: cos(60∘)=21.
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