The relationship between the basic trigonometric functions taking 3 times the angle in the trigonometric functions of those angles itself, gives The trigonometric triple-angle identities.
You can either expand or simplify the triple angle tan functions like tan 3 A , tan 3 x, tan 3 alpha etc by using triple angle identity.
Tan 3 theta = 3 tan theta – tan 3 theta / 1 – 3 tan2 theta
Where tan is a tangent function and theta is an angle. This is one of the important trigonometry formulas.
Tan 3x Formula Example:
Question: Find the value of A?
Tan 6 A X tan 3 A = 1
Solution: tan 6A =1 / tan 3 A
Tan 6A = cot 3A
Tan 6A = tan(90 – 3A)
6a = 90 – 3a
6A – 3A = 90
3A = 90
A = 30
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