Posted by Jay on Wednesday, January 23, 2013 at 8:14pm.
True or false?
tan x = tan(x6pi)

Trig  Reiny, Wednesday, January 23, 2013 at 9:32pm
Using tan(AB) = (tanA  tanB)/(1+tanAtanB)
RS = tan(x6π)
= (tanx  tan 6π)/(1 + tanxtan 6π)
but 6π is coterminal with 2π (6π is 3 rotations, and 2π is one rotation
so tan 6π = tan 2π = 0
= (tanx  0)/(1+ ) = tanx = LS
so the statement is true
or
tan(A) = tanA
so tan(x6π) =  tan(6πx)
= tan(2πx) , since 6π is coterminal with 2π
= ( tan(x) ) , by the CAST rule
= tanx