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Welcome to cos 55°, our post aboutthe cosine of 55 degrees.
For the cosine of 55 degrees we use the abbreviation cos for the trigonometric function together with the degree symbol °, and write it as cos 55°.
If you have been looking for what is cos 55°, or if you have been wondering about cos 55 degrees in radians, then you are right here, too.
In this post you can find the cos 55° value, along with identities.
Read on to learn all about the cos of 55°.
Cos 55 Degrees
If you want to know what is cos 55 degrees 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 55°:
cos 55° = 0.57358
cos 55 degrees = 0.57358
The cos of 55 degrees is 0.57358, the same as cos of 55 degrees in radians. To obtain 55 degrees in radian multiply 55° by $\pi$ / 180° = 11/36 $\pi$. Cos 55degrees = cos (11/36 × $\pi)$.
Our results of cos55° have been rounded to five decimal places. If you want cosine 55° with higher accuracy, then use the calculator below; our tool displays ten decimal places.
To calculate cos 55 degrees insert the angle 55 in the field labelled °, but if you want to calculate cos 55 in radians, then you have to press the swap unit button first.
Calculate cos [degrees]
The identities of cosine 55° are as follows:
= sin (90°+55°) = sin 145°
= sin (90°-55°) = sin 35°
-cos55°
= cos (180°+55°) = cos 235°
= cos (180°-55°) = cos 125°
There are more formulas for the double angle (2 × 55°), half angle ((55/2)°) as well as the sum, difference and products of two angles such as 55° and β.
You can locate all of them in the respective article found in the header menu. To find everything about cos -55° click the link. And here is all about sin 55°, including, for instance, a converter.
In terms of the other five trigonometric functions, cos of 55° =
- $\pm \sqrt{1-\sin^{2} 55 ^\circ}$
- $\pm\frac{1}{\sqrt{1 + \tan^{2} 55^\circ}}$
- $\pm\frac{\cot 55^\circ}{\sqrt{1 + \cot^{2} 55^\circ}}$
- $\frac{1}{\sec 55^\circ}$
- $\pm\frac{\sqrt{\csc^{2} 55^\circ – 1} }{\csc 55^\circ}$
As the cosine function is the reciprocal of the secant function, 1 / sec 55° = cos55°.
In the next part we discuss the trigonometric significance of cos55°, and there you can also learn what the search calculations form in the sidebar is used for.
What is cos 55°?
In a triangle which has one angle of 90 degrees, the cosine of the angle of 55° is the ratio of the length of the adjacent side a to the length of the hypotenuse h: cos 55° = a/h.
In a circle with the radius r, the horizontal axis x, and the vertical axis y, 55 degrees 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 55°.
Bringing together the triangle definition and the unit circle definition of cosine 55 degrees, a = x and h = r = 1. It follows that $x\hspace{5px} =\hspace{5px}\frac{adjacent}{hypotenuse}\hspace{5px}=\hspace{5px}\cos 55^\circ$.
Note that you can locate many terms including the cosine55° value using the search form. On mobile devices you can find it by scrolling down. Enter, for instance, value of cos55°.
Along the same lines, using the aforementioned form, can you look up terms such as cos 55° value, cos 55, cos55° value and what is the cos of 55 degrees, just to name a few.
Given the periodic property of cosine of 55°, to determine the cosine of an angle > 360°, e.g. 775°, calculate cos 775° as cos (775 Mod 360)° = cosine of 55°, or look it up with our form.
Conclusion
The frequently asked questions in the context include what is cos 55 degrees and what is the cos of 55 degrees for example; reading our content they are no-brainers.
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– Article written by Mark, last updated on February 17th, 2017