Given x is an acute angle and tanx = 1/5 how do you find tan2x and tan3x?

Answer 1

In general tan(x+y) = (tan x + tan y)/ (1- tan x tan y).
So tan 2x = 2 tan x/(1- tan² x) = 2/5 /(1-1/25) = 2/5 * 25/24 = 5/12.
Now carry it one step further:
tan 3x = (tan 2x + tan x)/(1 - tan 2x tan x)
= (5/12 + 1/5) / (11/12)
= 37/60 * 12/11 = 37/55.

Answer 2

tan x=0.2
tan x=tan 13 degrees.
find tan 26 and tan 39