Question

How do you solve `4 cot 4u = 2 cot 2u - 2 tan 2u`, within the interval [0,2pi)?

Answer 1

equation undefined

Explanation:

Reminder of trig identity:
`tan 4u = (2tan 2u)/(1 - tan^ 2u)`
Simplify both sides by 2 and develop the left side. The aim is selecting tan 2u as unique variable.
`LS = 2/(tan 4u) = (1 - tan^2 2u)/(tan 2u)`
Develop the right side:
`RS = 1/tan (2u) - tan 2u = (1 - tan^2 2u)/(tan 2u)`

Because LS - RS = 0, there fore, the equation is undefined.