Prove that cotA-tanA/cotA+tanA=cos2A

Steps to prove cotA-tanA/cotA+tanA=cos2A

Take cotA-tanA/cotA+tanA as L.H.S

= cotA-tanA/cotA+tanA

= 1/tanA-tanA / 1/tanA+tanA

= 1-tan^2A/tan^2A / 1+tan^2A/tan^A

= 1-tan^2A / 1+tan^B

= cos2A

= R.H.S

∴ Hence we prove cotA-tanA/cotA+tanA=cos2A

Detail Information:

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