Prove the identities:
sec2x−cosec2x≡tan2x−cot2x\sec^2x - \text{cosec}^2x \equiv \tan^2x - \cot^2xsec2x−cosec2x≡tan2x−cot2x
(secx−cosx)2≡tan2x−sin2x(\sec x - \cos x)^2 \equiv \tan^2x - \sin^2x(secx−cosx)2≡tan2x−sin2x
