Evaluate tan3A-tan2A-tanA
tan3Atan2AtanA
-tan3Atan2AtanA
tanAtan2A-tan2Atan3A-tan3AtanA
None of the above
Explanation for correct option
Evaluating the given trigonometric expression
Given, tan3A-tan2A-tanA
We know that,
3A=2A+A
Taking tan on both sides:
tan3A=tan(2A+A)⇒tan3A=tan2A+tanA1-tan2AtanA[∵tan(A+B)=tanA+tanB1-tanAtanB]⇒tan3A(1-tan2AtanA)=tan2A+tanA
Cross multiplying and simplifying further, we get,
⇒tan3A-tan3Atan2AtanA=tan2A+tanA
∴tan3A-tan2A-tanA=tan3Atan2AtanA
Hence, the correct answer is Option (A).