Tangent Addition Formula

Question

tan(x - 3 π ) = _____

-1

1

-tanx

tanx

Answer 1

tan (3*pi) = 0

Angle subtraction formula says:

tan(x - 3*pi) = { tanx - tan (3*pi)} / ( 1 + tanx * tan (3*pi)

= (tan x - 0) / ( 1 + tan x * 0)

= tan x / (1+0)

= tanx / 1

= tan x