Question

Find the primary solution of cosθ=−0.3

⁡

Answer 1

The solution of cos θ = −0.3 is θ = 107.45760312 degrees

Solution:

Given that we have to find the primary solution of
`cos \theta = -0.3`

To solve this equation, you must find the unknown (theta)

`cos \theta = -0.3`

Use the inverse of cosine (Arccos) to find the angle measurement (in degrees) of theta

`\theta = arccos (-0.3)`

We know that arccos (-0.3) = 107.45760312 degrees

[ If you reference a unit circle or use a calculator ]

`\theta = 107.45760312^(\circ)`

Therefore solution of cos θ = −0.3 is θ = 107.45760312 degrees