# Sin 100 Sin 20 Cos 250 Cos 190

Sin 100 Sin 20 Cos 250 Cos 190

## Cos 100 Degrees

The value of
cos 100 degrees is -0.1736481. . .. Cos 100 degrees in radians is written as cos (100° × π/180°), i.e., cos (5π/9) or cos (1.745329. . .). In this article, we will discuss the methods to find the value of cos 100 degrees with examples.

• Cos 100°:
-0.1736481. . .
• Cos (-100 degrees):
-0.1736481. . .

cos (5π/9) or cos (1.7453292 . . .)

## What is the Value of Cos 100 Degrees?

The value of cos 100 degrees in decimal is -0.173648177. . .. Cos 100 degrees can also be expressed using the equivalent of the given angle (100 degrees) in radians (1.74532 . . .)

We know, using degree to radian conversion, θ in radians = θ in degrees × (pi/180°)
⇒ 100 degrees = 100° × (π/180°) rad = 5π/9 or 1.7453 . . .
∴ cos 100° = cos(1.7453) = -0.1736481. . .

Explanation:

For cos 100 degrees, the angle 100° lies between 90° and 180° (Second Quadrant). Since cosine function is negative in the second quadrant, thus cos 100° value = -0.1736481. . .
Since the cosine function is a periodic function, we can represent cos 100° as, cos 100 degrees = cos(100° + n × 360°), n ∈ Z.
⇒ cos 100° = cos 460° = cos 820°, and so on.
Note:
Since, cosine is an even function, the value of cos(-100°) = cos(100°).

## Methods to Find Value of Cos 100 Degrees

The cosine function is negative in the 2nd quadrant. The value of cos 100° is given as -0.17364. . .. We can find the value of cos 100 degrees by:

• Using Trigonometric Functions
• Using Unit Circle

## Cos 100° in Terms of Trigonometric Functions

Using trigonometry formulas, we can represent the cos 100 degrees as:

• ± √(1-sin²(100°))
• ± 1/√(1 + tan²(100°))
• ± cot 100°/√(1 + cot²(100°))
• ±√(cosec²(100°) – 1)/cosec 100°
• 1/sec 100°

Note: Since 100° lies in the 2nd Quadrant, the final value of cos 100° will be negative.

We can use trigonometric identities to represent cos 100° as,

• -cos(180° – 100°) = -cos 80°
• -cos(180° + 100°) = -cos 280°
• sin(90° + 100°) = sin 190°
• sin(90° – 100°) = sin(-10°)

## Cos 100 Degrees Using Unit Circle

To find the value of cos 100 degrees using the unit circle:

• Rotate ‘r’ anticlockwise to form 100° angle with the positive x-axis.
• The cos of 100 degrees equals the x-coordinate(-0.1736) of the point of intersection (-0.1736, 0.9848) of unit circle and r.

Hence the value of cos 100° = x = -0.1736 (approx)

☛ Also Check:

• cos 240 degrees
• cos 3 degrees
• cos 37 degrees
• cos 59 degrees
• cos 63 degrees
• cos 65 degrees

## FAQs on Cos 100 Degrees

### What is Cos 100 Degrees?

Cos 100 degrees is the value of cosine trigonometric function for an angle equal to 100 degrees.

The value of cos 100° is -0.1736 (approx)

### What is the Value of Cos 100° in Terms of Sec 100°?

Since the secant function is the reciprocal of the cosine function, we can write cos 100° as 1/sec(100°). The value of sec 100° is equal to -5.758770.

Baca :   Harga Tetapan Kesetimbangan Kc Untuk Reaksi

### What is the Value of Cos 100 Degrees in Terms of Sin 100°?

Using trigonometric identities, we can write cos 100° in terms of sin 100° as, cos(100°) = -√(1 – sin²(100°)). Here, the value of sin 100° is equal to 0.9848.

### How to Find the Value of Cos 100 Degrees?

The value of cos 100 degrees can be calculated by constructing an angle of 100° with the x-axis, and then finding the coordinates of the corresponding point (-0.1736, 0.9848) on the unit circle. The value of cos 100° is equal to the x-coordinate (-0.1736). ∴ cos 100° = -0.1736.

### How to Find Cos 100° in Terms of Other Trigonometric Functions?

Using trigonometry formula, the value of cos 100° can be given in terms of other trigonometric functions as:

• ± √(1-sin²(100°))
• ± 1/√(1 + tan²(100°))
• ± cot 100°/√(1 + cot²(100°))
• ± √(cosec²(100°) – 1)/cosec 100°
• 1/sec 100°

☛ Also check: trigonometry table

### Sin 100 Sin 20 Cos 250 Cos 190

Sumber: https://www.cuemath.com/trigonometry/cos-100-degrees/

## Contoh Soal Perkalian Vektor

Contoh Soal Perkalian Vektor. Web log Koma – Setelah mempelajari beberapa operasi hitung pada vektor …