A community for students. Sign up today!
Here's the question you clicked on:
← 55 members online
 0 viewing
 2 years ago
cos^2x = cos x solve each equation for principal values of x. express solutions in degrees
 2 years ago
cos^2x = cos x solve each equation for principal values of x. express solutions in degrees

This Question is Open

Azteck
 2 years ago
Best ResponseYou've already chosen the best response.0Simplify cos(2x) first. \[\cos(2x)=\cos^{2}(x)\sin^{2}(x)\] \[=\cos^{2}(x)(1cos^{2}(x))\] \[=\cos^{2}(x)1+\cos^{2}(x)\] \[=2\cos^{2}(x)1\]  \[2\cos^{2}(x)1=\cos(x)\] \[2\cos^{2}(x)\cos(x)1=0\] \[(2\cos(x)+1)(\cos(x)1)=0\] \[\cos(x)=\frac{ 1 }{ 2 }\] or \[\cos(x)=1\] \[x=0, 120, 240, 360 \]
Ask your own question
Ask a QuestionFind 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.