Prove that: tan3Atan2AtanA=tan3A−tan2A−tanA
Determine the proof of the given expression tan3Atan2AtanA=tan3A−tan2A−tanA
Solve the L.H.S part:
Since we know that 3A=2A+A............................(i) taking the tan both sides of the above equation.tan3A=tan(2A+A)⇒tan3A=tan2A+tanA(1-tan2A.tanA)⇒tan3A(1-tan2AtanA)=tan2A+tanA⇒tan3A-tan3Atan2AtanA=tan2A+tanA⇒tan3A-tan2A-tanA=tan3Atan2AtanAHence, the L.H.S = R.H.S.