Let `f(x) = tanx - tan^3 +tan^5 x - tan^7 x+...........oo`, then which of the following-is/are correct?

tan 5x- tan 3x - tan 2x =

tanx + tan2x + tan3x=0

tan 5x tan3x tan2x=

tan 5x tan3x tan2x=

tan 5x.tan3x.tan 2x =

tan3x-tan2x-tan x=tan3x tan2x tan x

tanx + tan2x + tan3x = tanx tan2x tan3x

Let f : I - {-1,0,1} to [-pi, pi] be defined as f(x) = 2 tan^(-1) x - tan^(-1)((2x)/(1 -x^(2))) , then which of the following statements (s) is (are) correct ?

Let f : I - {-1,0,1} to [-pi, pi] be defined as f(x) = 2 tan^(-1) x - tan^(-1)((2x)/(1 -x^(2))) , then which of the following statements (s) is (are) correct ?