If the terminal side of an angle lies on the negative (y)-axis then what is the least positive radian angle?
Answer and explanation
Correct answer: \(\frac{3\pi}{2}\)
In standard position, a positive angle is measured anticlockwise from the positive x-axis. Reaching the negative y-axis requires three-fourths of a full revolution: \(270^\circ=\frac{3\pi}{2}\) radians. \(\frac{\pi}{2}\) represents the positive y-axis, while \(\pi\) represents the negative x-axis. Exam tip: remember the axis angles \(0,\frac{\pi}{2},\pi,\frac{3\pi}{2}\).
Frequently asked questions
What is the correct answer to this question?
\(\frac{3\pi}{2}\)
Why is this the correct answer?
In standard position, a positive angle is measured anticlockwise from the positive x-axis. Reaching the negative y-axis requires three-fourths of a full revolution: \(270^\circ=\frac{3\pi}{2}\) radians. \(\frac{\pi}{2}\) represents the positive y-axis, while \(\pi\) represents the negative x-axis. Exam tip: remember the axis angles \(0,\frac{\pi}{2},\pi,\frac{3\pi}{2}\).
Which subject and chapter does this question cover?
This is a Class 12 Mathematics question. Chapter: Trigonometric Functions. Topic: Angles.
