## What is theta when COS is 1 2?

Given that, cosθ=12 . But, it is known that, cos60°=12 . Also, cos300°=12 . ∴θ=60° & θ=300° .

**What is Cos inverse half?**

cos−1(12)=π3.

### Which value of cos is 1 2?

Precalculus Examples The exact value of arccos(12) arccos ( 1 2 ) is π3 . The cosine function is positive in the first and fourth quadrants. To find the second solution, subtract the reference angle from 2π to find the solution in the fourth quadrant.

**What is the half angle formula of cos theta?**

Key Equations

Double-angle formulas | sin(2θ)=2sin θ cos θ cos(2θ)=cos2θ−sin2θ =1−2sin2θ =2cos2θ−1 tan(2θ)=2tan θ1−tan2θ |
---|---|

Reduction formulas | sin2θ=1−cos(2θ)2 cos2θ=1+cos(2θ)2 tan2θ=1−cos(2θ)1+cos(2θ) |

Half-angle formulas | sin α2=±√1−cos α2 cos α2=±√1+cos α2 tan α2=±√1−cos α1+cos α =sin α1+cos α =1−cos αsin α |

## What is cos theta1?

⇒ θ = 2nπ ± 0°, n ∈ Z, [Since, the general solution of cos θ = cos ∝ is given by θ = 2nπ ± ∝, n ∈ Z.] Hence, the general solution of cos θ = 1 is θ = 2nπ, n ∈ Z.

**What is the value of minus 1 by 2 in cos theta?**

The exact value of arccos(−12) arccos ( – 1 2 ) is 2π3 2 π 3 .

### What is the value of Cos inverse 1 2?

cos-1(-1/2) Therefore, principal value of cos-1(-1/2) = 2π/3.

**What is the value of Cos inverse 1/2 )?**

Therefore, the principal value of cos-1( -1/2) is 2π /3.

## How do you find the inverse of Cos 1 2?

Principal value of cos−1(−1/2) is equal to

- A. π/3.
- B. 2π/3.
- C. −π/3.
- D. −2π/3.

**How do you solve Costheta?**

To solve this equation, you must find the unknown (theta). Use the inverse of cosine (Arccos) to find the angle measurement (in degrees) of theta. If you reference a unit circle or use a calculator, that would be 120 degrees. Hope this helped!

### What is sin30 value?

0.5

The value of sin 30 degrees is 0.5. Sin 30 is also written as sin π/6, in radians.

**What is the value of Cos inverse 2?**

As a Real valued function of Real angles cos(x):R→[−1,1] does not take the value 2 , or indeed any value in (−∞,−1)∪(1,∞) , so cos−1(2) is undefined.

## What equals cos 2theta?

The cosine double angle formula is cos(2theta)=cos2(theta) – sin2(theta). Combining this formula with the Pythagorean Identity, cos2(theta) + sin2(theta)=1, two other forms appear: cos(2theta)=2cos2(theta)-1 and cos(2theta)=1-2sin2(theta).

**What is cos 2x equal to?**

Cos2x is one of the double angle trigonometric identities as the angle in consideration is a multiple of 2, that is, the double of x. Let us write the cos2x identity in different forms: cos2x = cos2x – sin2x. cos2x = 2cos2x – 1.

### What is value of 1 cos theta?

Expert-verified answer The value of 1+cosΘ is 2sin²(Θ/2).

**What is Costheta?**

The Cos theta or cos θ is the ratio of the adjacent side to the hypotenuse, where θ is one of the acute angles.