Questions: An angle, θ, has a reference angle of π/6 radians, and the angle θ is between π and 3π/2. Determine the exact angle measure of θ in radians.
Transcript text: 5. [10 pts] An angle, $\theta$, has a reference angle of $\frac{\pi}{6}$ radians, and the angle $\theta$ is between $\pi$ and $\frac{3 \pi}{2}$. Determine the exact angle measure of $\theta$ in radians.
Solution
Solution Steps
Step 1: Understand the reference angle
The reference angle is given as \(\frac{\pi}{6}\) radians. A reference angle is the smallest angle between the terminal side of \(\theta\) and the x-axis.
Step 2: Determine the quadrant of \(\theta\)
The problem states that \(\theta\) lies between \(\pi\) and \(\frac{3\pi}{2}\), which is the third quadrant. In the third quadrant, the angle \(\theta\) can be expressed as:
\[
\theta = \pi + \text{reference angle} = \pi + \frac{\pi}{6}.
\]
Step 3: Calculate the exact angle measure
Substitute the reference angle into the expression:
\[
\theta = \pi + \frac{\pi}{6} = \frac{6\pi}{6} + \frac{\pi}{6} = \frac{7\pi}{6}.
\]
Thus, the exact measure of \(\theta\) is \(\frac{7\pi}{6}\) radians.