Question

How do you solve `tan^-1 3x + tan^-1 (x+1) = tan^-1 (1/3)`?

Answer 1

Solve trig equation

Explanation:

`arctan 3x + arctan (x + 1) = arctan (1/3) = 18^@43` (by calculator)
We have 3x + (x + 1) = 18.43
4x = 17.43 --> `x = 4^@38`
Check by calculator.
3x = 17.43 --> tan 3x = 0.23
(x + 1) = 5.38 --> tan 5.38 = 0. 1
tan 3x + tan (x + 1) = 0.33 --> `tan (1/3)`. OK