I can't straight away see how this one can be solved.
But I would suggest having a look at the indentities for and
Given sin( π/5 ) = 0.588 and cos ( π/8 ) = 0.924
How can you figure out cos ( 27π/8 )?
I can't think of any trig identities/formulas that would fit the problem. Help please?
Thanks in advance.
(π is pi btw)