# What is COS equal to?

## What is COS equal to?

Definition of cosine The cosine of an angle is defined as the sine of the complementary angle. The complementary angle equals the given angle subtracted from a right angle, 90°. cos θ = sin (90° – θ). Written in terms of radian measurement, this identity becomes. cos θ = sin (π/2 – θ).

**What is cos a B?**

cos(A + B) = cos A cos B − sin A sin B.

### What is trigonometry formula?

Basic Trigonometric Function Formulas By using a right-angled triangle as a reference, the trigonometric functions and identities are derived: sin θ = Opposite Side/Hypotenuse. cos θ = Adjacent Side/Hypotenuse. tan θ = Opposite Side/Adjacent Side.

**What is sin a and sin B?**

Simply, it states that the ratio of the length of a side of a triangle to the sine of the angle opposite that side is the same for all sides and angles in a given triangle. In ΔABC is an oblique triangle with sides a,b and c , then asinA=bsinB=csinC .

#### What is the value of sin 15?

The actual value of sin 15 degrees is (√3−1)/(2√2).

**What is the value of sin 15 and cos 15?**

Finally, we have tan15∘=sin15∘cos15∘=√6−√2√6+√2=(√6−√2)2(√6+√2)(√6−√2)=6+2−2√2√66−2=8−2√124=2−√3.

## How do you find the value of cos 15?

Answer: The value of cos 15 = √3+1/2√2

- sin 0° = √(0/4) = 0.
- sin 30° = √(1/4) = ½
- sin 45° = √(2/4) = 1/√2.
- sin 60° = √3/4 = √3/2.
- cos 90° = √(4/4) = 1.

**What is the value of sin 75?**

Hence the value of Sin 75 degree is equal to (√3 + 1) / 2√2.

### What is the value cos 30?

Cos 30 degrees is written as cos 30° and has a value in fraction form as √3/2. Cos 30° = √3/2 is an irrational number and equals to 0.8660254037 (decimal form). Therefore, the exact value of cos 30 degrees is written as 0.8660 approx.

**What is COS 1 in radians?**

As you can see below, the cos-1 (1) is 270° or, in radian measure, 3Π/2 .

#### What is value of cos 90 degree?

Therefore, the value of cos 90 degrees is: Cos 90° = 0. It is observed that the values of sin and cos functions do not change if the values of x and y are the integral multiples of 2π.

**Is Cos 90 positive or negative?**

The coordinates of point A, B, C and D are stated as (1, 0), (0, 1), (-1,0) and (0. -1) respectively. We will get the Cos 90 value through the quadrant angle….

Degrees | Quadrant | Cosine Function Sign |
---|---|---|

90 to 180 Degrees | 2nd Quadrant | Negative |

180 to 270 Degrees | 3rd Quadrant | Negative |

270 to 360 Degrees | 4th Quadrant | Positive |

## Why is tan 90 undefined?

Why is Tan 90 undefined? As we have got the result as infinity, and we cannot define infinity, therefore tan 90 is undefined.

**Can you do cos 90?**

Since in cos 90, base is 0, therefore therefore cos 90 is zero. if you go to the basic definition of trigonometric ratios, when you take a point at an angle 90 degrees, the x cordinate is zero, so cosine of 90degree is zero.

### Why is the sine of 90 degrees 1?

Now the value of y becomes 1 since it touches the circumference of the circle. Therefore the value of y becomes 1. Therefore, sin 90 degree equals to the fractional value of 1/ 1.