Answer:
"Haruto is correct because the angle is coterminal with 3pi/4 and the reference angle is pi/4."
Explanation:
Coterminal angle:
Coterminal Angles are angles who share the same initial side and terminal sides. Finding coterminal angles is as simple as adding or subtracting 360° or 2π to each angle, depending on whether the given angle is in degrees or radians.
Finding if 3pi/4 is coterminal with 19pi/4:
19pi/4
= 16pi/4 + 3pi/4
= 4pi + 3pi/4
= 2(2pi) + 3pi/4
= 2(360°) + 3pi/4
= 3pi/4
Hence they are coterminal.
Reference angle:
The smallest angle that the terminal side makes with x-axis.
3pi/4 falls in second quadrant.
In 2nd quadrant, reference angle is given as = pi - 3pi/4
reference angle = pi/4.