Using your calculator
WARNING! Before you can use the Sin, Cos or Tan buttons for GCSE, you need to ALWAYS make sure that your calculator is set to DEGREE mode. If it is in degree mode, a tiny D or maybe the word Deg should appear somewhere on your screen. If you don’t have this and have R (or Rad) or G (or Gra), please consult your calculator manual or ask your teacher to show you how to reset your calculator. Once you have been shown how to do this REMEMBER IT and EVERY time you use the calculator for Trigonometry questions, ALWAYS check if your are in the correct (D/Deg) mode first!
On your calculator are three buttons which are labelled Sin, Cos and Tan. These buttons are meaningless on their own (ie you can’t have a Sin). They can only be used with an angle eg Sin30, or Cos53.5 etc. Using these buttons is very easy – just type what you see:
Eg. Sin30 type the sin button, then type 30, then press the = button
The calculator should show 0.5.
Etc
Sometimes you need to use the calculator to find an angle. In this case use the SHIFT button first. Another way of knowing when to use the SHIFT button is to ask yourself, “Can I type the question into the calculator as it is written?”. If the answer is NO, then use SHIFT.
Eg. You can’t type this into the calculator, so type:
SHIFT, then sin, then 0.5, then =
The calculator should show 30.