Question

Which of the following is a quadrantal angle​

Answer 1

Question:

Which of the following is a quadrantal angle?

a) π/2        b) π/3        c) 2π/3      D) 4π/5​

Answer:

$(a)\ \frac{\pi}{2}$

Step-by-step explanation:

Required

Which of a to d is a quadrantal angle

An angle is said to be quadrantal if and only if the angle has its terminal side on the x or y axis.

Such angles (in degrees) are: 90, 180, 270, etc.

So, we have:

$(a)\ \frac{\pi}{2}$

[Convert to degrees]

$\frac{\pi}{2} = \frac{180}{2}$

$\frac{\pi}{2} = 90$

Hence:

$(a)\ \frac{\pi}{2}$ is a quadrantal angle

The other options are not.