Thanks guys, I got it to work with the following code, I then added a bit more on to see how much i could do. But i have 2 questions. Firstly why do you have to put "int" in front of "main ()" as we did not have to that for other stuff we learned in class.
and second of all, I had to use integers for the yes/no part at the end, because I couldn't figure out how to just use the input "y" or "n". How could I've done this instead?
printf("welcome to the cos calculator\n");
printf("what angle do you want the cos of):\n");
printf("are you happy with the answer?(yes=1/no=0)\n");
printf("Too bad, it's right!\n");
Many thanks, alex