Question

Find all values of θ, if θ is in the interval [0, 360°) and has the given function value.

Answer 1

Remember that cosine is positive in the first and fourth quadrants.

To get the angle that's in the first quadrant, we solve for Theta as following:

`\begin{gathered} \cos \theta=\frac{\sqrt[]{3}}{2} \\ \\ \rightarrow\theta=\cos ^(-1)(\frac{\sqrt[]{3}}{2}) \\ \\ \Rightarrow\theta=30 \end{gathered}`

To get the angle in teh fourth quadrant, we substract the calculated angle from 360°

`360-30=330`

Therefore, the two angles we're looking for are 30° and 330°