Question

Can someone help me with this:
Find all solutions in the interval [0, 2pi) .
7 tan^3x - 21 tan x = 0

Answer 1

try factoring tan(x) out first, so tan(x) = 0, recall identities to replace tan^2 and tan by sin and cos maybe

Answer 2

those probs just play around till you get something in terms of sin and cos using identities and algebra

Answer 3

\[7\tan(x)[\tan^2(x) -3]=0\]

\[7\tan(x)[\frac{ \sin^2(x) }{ \cos^2(x) } -3]=0\]

Answer 4

Here

Answer 5

On the very left its pie.k and not pie

Answer 6

@DanJS what are you doing ? :s

Answer 7

I mean very right* on the bottom +pie.k

Answer 8

lol idk, you have it right,

use the unit circle, tan(x)=y/x, remember symmetries if needed for multiple answers over the domain

Answer 9

Thats better

Answer 10

looks right

Answer 11

Oh and since its limited between ]0,2pie[
Then you write my answer and add for k=0,1,2