Chapter 10.4, Problem 10PE

For Exercises 9-14, assume that the $x\text{-}$ and $y\text{-axes}$ are rotated through angle $\theta$ about the origin to form the $x\text{'}\text{-}$ and $y\text{'}\text{-axes}$ . (See Example 2)

Given $\theta =30°$ and $P\left(-4,8\right)$ in the $xy\text{-plane,}$ find the coordinates of $P$ in the $x\text{'}y\text{'}\text{-plane}$ .