A community for students.
Here's the question you clicked on:
 0 viewing
Lukecrayonz
 2 years ago
cos 4x  cos 2x = 0
Find all solutions to the equation in the interval [0, 2ð).
ð, pi/3 2pi/3 4pi/3 5pi/3, 0?
Is that correct?
Lukecrayonz
 2 years ago
cos 4x  cos 2x = 0 Find all solutions to the equation in the interval [0, 2ð). ð, pi/3 2pi/3 4pi/3 5pi/3, 0? Is that correct?

This Question is Closed

ganeshie8
 2 years ago
Best ResponseYou've already chosen the best response.1\(\cos^4 x  \cos^2x = 0\) is the equation like above ?

Lukecrayonz
 2 years ago
Best ResponseYou've already chosen the best response.1No, Cos(4x)cos(2x)=0

Lukecrayonz
 2 years ago
Best ResponseYou've already chosen the best response.1@ganeshie8 no idea?:(

ganeshie8
 2 years ago
Best ResponseYou've already chosen the best response.1could u show me ur work

Lukecrayonz
 2 years ago
Best ResponseYou've already chosen the best response.1cosx=cos(x+2kpi) Apply Cos C  Cos D formula Cos C  Cos D = 2sin(C+D)/2 Sin(DC)/2

Lukecrayonz
 2 years ago
Best ResponseYou've already chosen the best response.1So 0, pi/3, 2pi/3, 4pi/3, 5pi/3 and ð

Lukecrayonz
 2 years ago
Best ResponseYou've already chosen the best response.1@anas2000 can you help?:D

ganeshie8
 2 years ago
Best ResponseYou've already chosen the best response.1hmm that doesnt help me

Lukecrayonz
 2 years ago
Best ResponseYou've already chosen the best response.1@UnkleRhaukus @robtobey

ganeshie8
 2 years ago
Best ResponseYou've already chosen the best response.1cos 4 x  cos 2 x = 0 2cos^2 2x1  cos 2x = 0 2u^2 u 1 = 0 (u1)(2u+1) = 0 u = 1; u = 1/2 cos 2x = 1 ; cos 2x = 1/2 2x = 0 ; 2x = pipi/3, 2x = pi + pi/3 x = 0 + npi; x = pi/3 + npi, x = 2pi/3 + npi x = 0, pi; x = pi/3, 4pi/3, x = 2pi/3, 5pi/3 so solutions will be : x = 0, pi/3, 2pi/3, 4pi/3, 5pi/3, pi looks you got the same solutions wid very less effort... !

ganeshie8
 2 years ago
Best ResponseYou've already chosen the best response.1np... yw :) good work !
Ask your own question
Sign UpFind more explanations on OpenStudy
Your question is ready. Sign up for free to start getting answers.
spraguer
(Moderator)
5
→ View Detailed Profile
is replying to Can someone tell me what button the professor is hitting...
23
 Teamwork 19 Teammate
 Problem Solving 19 Hero
 Engagement 19 Mad Hatter
 You have blocked this person.
 ✔ You're a fan Checking fan status...
Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.