A community for students. Sign up today!
Here's the question you clicked on:
← 55 members online
 0 viewing
 2 years ago
Stuck on Trig identities! :( Help please~
How do I prove
cos(x+y)cosy + sin(x+y)siny = cosx??
 2 years ago
Stuck on Trig identities! :( Help please~ How do I prove cos(x+y)cosy + sin(x+y)siny = cosx??

This Question is Closed

tanjung
 2 years ago
Best ResponseYou've already chosen the best response.1just to understanding the formula : cosAcosB + sinAsinB = cos(AB)

pottersheep
 2 years ago
Best ResponseYou've already chosen the best response.0I cant get the answer still though

tanjung
 2 years ago
Best ResponseYou've already chosen the best response.1change A to (x+y) and B to y

pottersheep
 2 years ago
Best ResponseYou've already chosen the best response.0I got it! Ha, it was easier than I thought :)

pottersheep
 2 years ago
Best ResponseYou've already chosen the best response.0You can have the medal :)
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.