What is the exact value of sin 12 degrees?
Only hint I was given was to use compound angle formula. Had this on the test but I left it blank, now I just want to know the solution.
We know the values of the trig functions for and so if we also know the trig function values for we are home and dry.
We can get the values we need for the and of from the geometry of a regular pentagon (which we could have guessed as we are dealing with integer fractions of , where we find:
where is the Golden number.