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View Full Version : I need help to verify this: sin(2x)/(csc(x)*cos(x)) = 2 - 2cos^2(x)


brilw22
Apr 11, 2013, 08:21 PM
Verifying identies

ebaines
Apr 12, 2013, 06:53 AM
As usual - first thing is to convert the csc(x) function to it's sine equivalent. Then apply the identity for sin(2x) - if you don't know it off the top of your head you need to memorize it. Finally look for other identities that can simplify things - one of the most common that shows up in these sorts of problems is sin^2x + cos^2x = 1, and its alternative forms such as sin^2x = 1 - cos^2x.