Question

Find all solutions in the interval [0, 2π).

7 tan^3x - 21 tan x = 0

Answer 1

Let u = tanx
Then, the equation becomes
\[7u^3-21u=0\]Factorize the left, you'll get\[7u(u^2-3) = 0\]Can you solve u from here?

Answer 2

I just did some of the work on scratch paper from the help of the lessons. Would you mind double checking my work?

Answer 3

I don't mind. Please post it :)

Answer 4

I got 0, pi/3, 2pi/3, pi, 4pi/3, 5pi/3?

Answer 5

Yup :)

Answer 6

Thank you!