Question

find all solutions:

cos 3x - cos x = 0

Answer 1

Factor

Answer 2

cos x (3-1)=0?

Answer 3

\[\cos^3x-cosx=cosx(\cos^2x-1)\]

Answer 4

\[\cos^2x-1=0\]\[cosx=0\]

Answer 5

well thats not the answer.... it is suppose to be intervals

Answer 6

Yes, can solve it from there?

Answer 7

and do you mean from (0, 2pi]?

Answer 8

i dont really understand how you factored that....

Answer 9

the answer said its

x= pi k, pi/2 + pi k

Answer 10

It is cos^3x-cosx right?

Answer 11

no.... it is simply Cos 3x - Cos x=0

Answer 12

>.<

Answer 13

lol,

Answer 14

Well I'm not much help then.. 66 can take care of you from here.

Answer 15

he left

Answer 16

I don't know whether I can help or not, let my try

Answer 17

I figure out if i go on that way, I will drive you crazy. give me time.

Answer 18

hmmm, I don't really understand. thanks