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View Full Version : Prove the Identity: 2cos^2x-1=(1-tan^2x)/(1 tan^2x)

michtheunicorn
Mar 29, 2012, 06:23 PM
2cos^2x-1=(1-tan^2x)/(1 + tan^2x)
ebaines
Mar 30, 2012, 05:10 AM
Convert tanx to sinx/cosx, and remember that sin^2x = 1 - cos^2x. It works out nicely.