A. Yes. The calculator has a two or three angle modes, and you need to check to make sure that the currently selected angle mode is the correct one for the type of calculation you are trying to perform. If it isn’t, you need to change it.
Determining the Current Angle mode Setting
The “angle” setting on the calculator’s setup screen will show one of the three angle unit indicators described below.
Degree:
If “DEG” is on the display, it means that the current angle mode is Degree.
A degree is 1/360 of the circumference of a circle. One degree is represented as 1゜.
The following are calculations that use degrees.
sin 90°= cos 0°=1
Radian:
If “Rad” is on the display, it means that the current angle mode is Radian.
A radian is 1/2πr of the circumference of a circle. Measurement of angles using radians called the “radian system of angular measurement”. 1 radian = 360゜/(2π)
The following are calculations that use radians.
sin(π/2)=1 cos (2π)=1
Grad:
If “Gra” is on the display, it means that the current angle mode is Grad. Note that ClassPad300 does not have a Grad angle mode.
A grad is 1/400 of the circumference of a circle.
The following are calculations that use grads.
sin 100 grads=cos 400 grads=1
The following shows the relationship between the three angle modes.
90°=π/2 radians=100grads
Radian is the initial default angle mode for a graphic scientific calculator.