Cos 1 Degrees
The value of cos 1 degrees is 0.9998476. . .. Cos 1 degrees in radians is written as cos (1° × π/180°), i.e., cos (0.017453. . .). In this article, we will discuss the methods to find the value of cos 1 degrees with examples.
- Cos 1°: 0.9998476. . .
- Cos (-1 degrees): 0.9998476. . .
- Cos 1° in radians: cos (0.0174532 . . .)
What is the Value of Cos 1 Degrees?
The value of cos 1 degrees in decimal is 0.999847695. . .. Cos 1 degrees can also be expressed using the equivalent of the given angle (1 degrees) in radians (0.01745 . . .)
We know, using degree to radian conversion, θ in radians = θ in degrees × (pi/180°)
⇒ 1 degrees = 1° × (π/180°) rad = 0.0174 . . .
∴ cos 1° = cos(0.0174) = 0.9998476. . .
Explanation:
For cos 1 degrees, the angle 1° lies between 0° and 90° (First Quadrant). Since cosine function is positive in the first quadrant, thus cos 1° value = 0.9998476. . .
Since the cosine function is a periodic function, we can represent cos 1° as, cos 1 degrees = cos(1° + n × 360°), n ∈ Z.
⇒ cos 1° = cos 361° = cos 721°, and so on.
Note: Since, cosine is an even function, the value of cos(-1°) = cos(1°).
Methods to Find Value of Cos 1 Degrees
The cosine function is positive in the 1st quadrant. The value of cos 1° is given as 0.99984. . .. We can find the value of cos 1 degrees by:
- Using Unit Circle
- Using Trigonometric Functions
Cos 1 Degrees Using Unit Circle
To find the value of cos 1 degrees using the unit circle:
- Rotate ‘r’ anticlockwise to form 1° angle with the positive x-axis.
- The cos of 1 degrees equals the x-coordinate(0.9998) of the point of intersection (0.9998, 0.0175) of unit circle and r.
Hence the value of cos 1° = x = 0.9998 (approx)
Cos 1° in Terms of Trigonometric Functions
Using trigonometry formulas, we can represent the cos 1 degrees as:
- ± √(1-sin²(1°))
- ± 1/√(1 + tan²(1°))
- ± cot 1°/√(1 + cot²(1°))
- ±√(cosec²(1°) - 1)/cosec 1°
- 1/sec 1°
Note: Since 1° lies in the 1st Quadrant, the final value of cos 1° will be positive.
We can use trigonometric identities to represent cos 1° as,
- -cos(180° - 1°) = -cos 179°
- -cos(180° + 1°) = -cos 181°
- sin(90° + 1°) = sin 91°
- sin(90° - 1°) = sin 89°
☛ Also Check:
Examples Using Cos 1 Degrees
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Example 1: Find the value of 2 cos(1°)/3 sin(89°).
Solution:
Using trigonometric identities, we know, cos(1°) = sin(90° - 1°) = sin 89°.
⇒ cos(1°) = sin(89°)
⇒ Value of 2 cos(1°)/3 sin(89°) = 2/3 -
Example 2: Find the value of cos 1° if sec 1° is 1.0001.
Solution:
Since, cos 1° = 1/sec 1°
⇒ cos 1° = 1/1.0001 = 0.9998 -
Example 3: Find the value of (cos² 0.5° - sin² 0.5°). [Hint: Use cos 1° = 0.9998]
Solution:
Using the cos 2a formula,
(cos² 0.5° - sin² 0.5°) = cos(2 × 0.5°) = cos 1°
∵ cos 1° = 0.9998
⇒ (cos² 0.5° - sin² 0.5°) = 0.9998
FAQs on Cos 1 Degrees
What is Cos 1 Degrees?
Cos 1 degrees is the value of cosine trigonometric function for an angle equal to 1 degrees. The value of cos 1° is 0.9998 (approx)
How to Find Cos 1° in Terms of Other Trigonometric Functions?
Using trigonometry formula, the value of cos 1° can be given in terms of other trigonometric functions as:
- ± √(1-sin²(1°))
- ± 1/√(1 + tan²(1°))
- ± cot 1°/√(1 + cot²(1°))
- ± √(cosec²(1°) - 1)/cosec 1°
- 1/sec 1°
☛ Also check: trigonometry table
How to Find the Value of Cos 1 Degrees?
The value of cos 1 degrees can be calculated by constructing an angle of 1° with the x-axis, and then finding the coordinates of the corresponding point (0.9998, 0.0175) on the unit circle. The value of cos 1° is equal to the x-coordinate (0.9998). ∴ cos 1° = 0.9998.
What is the Exact Value of cos 1 Degrees?
The exact value of cos 1 degrees can be given accurately up to 8 decimal places as 0.99984769.
What is the Value of Cos 1 Degrees in Terms of Tan 1°?
We know, using trig identities, we can write cos 1° as 1/√(1 + tan²(1°)). Here, the value of tan 1° is equal to 0.017455.
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