In which quadrant will the terminal side of \(\frac{31\pi}{6}\) lie?
Answer and explanation
Correct answer: Third
Subtract a multiple of \(2\pi\) to obtain a coterminal angle: \(\frac{31\pi}{6}-4\pi=\frac{31\pi}{6}-\frac{24\pi}{6}=\frac{7\pi}{6}\). Since \(\pi<\frac{7\pi}{6}<\frac{3\pi}{2}\), the terminal side lies in the third quadrant. It is \(\frac{\pi}{6}\) past \(\pi\), so the second quadrant is not correct. Exam tip: First reduce a radian angle to a coterminal angle between \(0\) and \(2\pi\).
Frequently asked questions
What is the correct answer to this question?
Third
Why is this the correct answer?
Subtract a multiple of \(2\pi\) to obtain a coterminal angle: \(\frac{31\pi}{6}-4\pi=\frac{31\pi}{6}-\frac{24\pi}{6}=\frac{7\pi}{6}\). Since \(\pi<\frac{7\pi}{6}<\frac{3\pi}{2}\), the terminal side lies in the third quadrant. It is \(\frac{\pi}{6}\) past \(\pi\), so the second quadrant is not correct. Exam tip: First reduce a radian angle to a coterminal angle between \(0\) and \(2\pi\).
Which subject and chapter does this question cover?
This is a Class 12 Mathematics question. Chapter: Trigonometric Functions. Topic: Angles.
