
Yes, the CTIFREE FX-991MS scientific calculator allows you to switch between degrees and radians for trigonometric calculations. Here's how to change the angle unit: First, press the "MODE" button on the calculator. Then, use the navigation keys (often arrow keys) to navigate through the mode options until you find the angle unit settings. You'll typically see options such as degrees (DEG), radians (RAD), and sometimes gradients (GRAD). Press the key associated with the angle unit you want to use (usually the "DRG" button or similar) to cycle through the options. Finally, press the "MODE" button again to confirm your selection and exit the menu. For visual guidance and model-specific instructions, consult the user manual that came with your CTIFREE FX-991MS calculator, as button labels and navigation might have slight variations.


