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Cos 2π/3

Welcome to cos 2π/3, our post aboutthe cosine of 2π/3.

For the cosine of 2π/3 we use the abbreviation cos for the trigonometric function and write it as cos 2π/3.

If you have been looking for what is cos 2π/3, or if you have been wondering about cos 2π/3 radians in degrees, then you are right here, too.

In this post you can find the cos 2π/3 value, along with identities.

Read on to learn all about the cos of 2π/3.

Cos 2π/3 Radians

If you want to know what is cos 2π/3 radians in terms of trigonometry, then navigate straight to the explanations in the next paragraph; what’s ahead in this section is the value of cos 2π/3:

cos2π/3 = -1/2
cos 2π/3 = -1/2
cos 2π/3 radians = -1/2

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The cos of 2π/3 radians is -1/2, the same as cos of 2π/3 radians in degrees. To change 2π/3 radians to degrees multiply 2π/3 by by 180° / $\pi$ = 120°. Cos 2π/3 = cos 120 degrees.

Our results of cos2π/3 have been rounded to five decimal places. If you want cosine 2π/3 with higher accuracy, then use the calculator below; our tool displays ten decimal places.

To calculate cos 2π/3 radians insert the angle 2π/3 in decimal notation, but if you want to calculate cos 2π/3 in degrees, then you have to press the swap unit button first.

Calculate cos [radians]

A Really Cool Cosine Calculator and Useful Information! Please ReTweet. Click To TweetBesides cos2π/3, similar trigonometric calculations on our site include, but are not limited, to:

The identities of cosine 2π/3 are as follows:

cos2π/3
= sin (π/2 + 2π/3) = sin 7/6 π
= sin (π/2 – 2π/3) = sin -1/6 π

-cos2π/3
= cos (π + 2π/3) = cos 5/3 π
= cos (π – 2π/3) = cos 1/3 π

Note that cos2π/3 is periodic: cos (2π/3 + n × 2π) = cos 2π/3, n$\hspace{5px} \in \hspace{5px} \mathbb{Z}$.

There are more formulas for the double angle (2 × 2π/3), half angle ((2π/3/2)) as well as the sum, difference and products of two angles such as 2π/3 and β.

You can locate all of them in the respective article found in the header menu. To find everything about cos -2π/3 click the link. And here is all about sin 2π/3, including, for instance, a converter.

In terms of the other five trigonometric functions, cos of 2π/3 =

  • $\pm \sqrt{1-\sin^{2} 2\pi/3 }$
  • $\pm\frac{1}{\sqrt{1 + \tan^{2} 2\pi/3}}$
  • $\pm\frac{\cot 2\pi/3}{\sqrt{1 + \cot^{2} 2\pi/3}}$
  • $\frac{1}{\sec 2\pi/3}$
  • $\pm\frac{\sqrt{\csc^{2} (2\pi/3) – 1} }{\csc 2\pi/3}$

As the cosine function is the reciprocal of the secant function, 1 / sec 2π/3 = cos2π/3.

In the next part we discuss the trigonometric significance of cos2π/3, and there you can also learn what the search calculations form in the sidebar is used for.

What is cos 2π/3?

In a circle with the radius r, the horizontal axis x, and the vertical axis y, 2π/3 is the angle formed by the two sides x and r; r moving counterclockwise is the positive angle.

As detailed in the unit-circle definition on our homepage, assumed r = 1, in the intersection of the point (x,y) and the circle, x = cos 2π/3.

Note that you can locate many terms including the cosine2π/3 value using the search form. On mobile devices you can find it by scrolling down. Enter, for instance, value of cos2π/3.

Along the same lines, using the aforementioned form, can you look up terms such as cos 2π/3 value, cos 2π/3, cos2π/3 value and what is the cos of 2π/3 radians, just to name a few.

Given the periodic property of cosine of 2π/3, to determine the cosine of an angle > 2π, e.g. 14/3 π, calculate cos 14/3 π as cos (14/3 π mod 2π) = cosine of 2π/3, or look it up with our form.

Conclusion

Cos 2π/3The frequently asked questions in the context include what is cos 2π/3 radians and what is the cos of 2π/3 degrees for example; reading our content they are no-brainers.

But, if there is something else about cosine 2π/3 you would like to know, fill in the form on the bottom of this post, or send us an email with a subject line such as cosine 2π/3 radians.

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Thanks for visiting cos2π/3 radians.

– Article written by Mark, last updated on February 26th, 2017

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