Hey anil86.
I'd suggest you take a look at the sum-to-product and product-to-sum identities (and keeping in mind the relation cos(ix) and cosh(x) and so on).
List of trigonometric identities - Wikipedia, the free encyclopedia
Hey anil86.
I'd suggest you take a look at the sum-to-product and product-to-sum identities (and keeping in mind the relation cos(ix) and cosh(x) and so on).
List of trigonometric identities - Wikipedia, the free encyclopedia