Q11 of 25 Page 3

Prove that tan 3x tan 2x tan x = tan 3x – tan 2x – tan x.

As 3x = 2x + x


⇒ tan 3x = tan (2x+x)


As we know,




⇒ tan 3x(1 – tan 2x tan x) = tan 2x + tan x


⇒ tan 3x – tan 3x tan 2x tan x = tan 2x + tan x


⇒ tan 3x tan 2x tan x = tan 3x – tan 2x – tan x


Hence proved.


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