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Choose the correct option. tan A+ tan (60°+ A) -tan (60°- A) is equal to?
(1) 3 tan(3A) (2) 3 tan(3A) (3) cot(3A) (4) sin(3A)
We can make use of trigonometric formulas to simplify expressions with complex trigonometric terms.
Answer: The value of the expression comes out to be 3 tan(3 A)
Go through the steps to find the exact value.
Explanation:
Given expression: tan A + tan (60° + A) - tan (60° - A)
On simplifying the given expression using the formula tan (x + y) = (tan x + tan y) / (1 - tan x tan y) and tan(3 A) = (3tan A - tan3 A) / (1 - 3 tan2 A)
tan A + tan (60° + A) - tan (60° - A)
= tan A + (tan 60° + tan A) / (1 - tan 60° tan A) - (tan 60° - tan A) / (1 + tan 60° tan A)
= tan A + (√3 + tan A) / (1 - √3 tan A) - (√3 - tanA) / (1 + √3 tan A)
= tan A + (√3 + 3 tan A + tan A + √3 tan2A - √3 + 3 tan A - √3 tan2 A + tanA) / (1 - 3 tan2 A)
= tan A + (8 tan A) / (1 - 3 tan2 A)
= (tan A - 3tan3 A + 8 tan A) / (1 - 3tan2 A)
= 3 (3 tan A - tan3 A) / (1 - 3tan2 A)
= 3 tan(3A)
Thus, the value of the expression comes out to be 3 tan(3A).
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