A community for students.
Here's the question you clicked on:
 0 viewing
Edutopia
 2 years ago
question about the proof of trig addition formulas for cos:
Edutopia
 2 years ago
question about the proof of trig addition formulas for cos:

This Question is Closed

Edutopia
 2 years ago
Best ResponseYou've already chosen the best response.0sorry about the scrolling: http://en.wikipedia.org/wiki/Proofs_of_trigonometric_identities on the part with the diagram for trig addition formulas, where does "RPQ = (PI/2)  RPQ" come from?

Edutopia
 2 years ago
Best ResponseYou've already chosen the best response.0also any sites with a better, easy to understand, definition would be greatly appriciated

AccessDenied
 2 years ago
Best ResponseYou've already chosen the best response.1RPQ = pi/2  RQP pi/2 radians is 90 degrees. RPQ = 90 degrees  RQP which we can see because that triangle is a right triangle, so the other two angles have to be complementary to add up to 180 degrees interior.

Edutopia
 2 years ago
Best ResponseYou've already chosen the best response.0but PRQ is only one of the complementary angles, how do i know that it is half of 90?

AccessDenied
 2 years ago
Best ResponseYou've already chosen the best response.1I believe PRQ is meant to be a right angle, 90 degrees or pi/2 radians, although it doesn't appear to be indicated as such...

AccessDenied
 2 years ago
Best ResponseYou've already chosen the best response.1dw:1357875756276:dw Just drawing diagram here

Edutopia
 2 years ago
Best ResponseYou've already chosen the best response.0im sorry we got it switched around somewhere its RPQ not PQR

Edutopia
 2 years ago
Best ResponseYou've already chosen the best response.0they are proving that RPQ=alpha

AccessDenied
 2 years ago
Best ResponseYou've already chosen the best response.1Since PRQ is a right triangle with right angle PRQ, RPQ and RQP are complementary. <RPQ + <RQP + <PRQ = 180 <RPQ + <RQP + 90 = 180 <RPQ + <RQP = 90 <RPQ = 90  <RQP Would that make sense?

Edutopia
 2 years ago
Best ResponseYou've already chosen the best response.0OH RPQ is a TRIANGLE! oops

AccessDenied
 2 years ago
Best ResponseYou've already chosen the best response.1the pi/2 is just radians, i was using degrees. sorry if that is confusing...

Edutopia
 2 years ago
Best ResponseYou've already chosen the best response.0no its not i understand radians

Edutopia
 2 years ago
Best ResponseYou've already chosen the best response.0aha i see it, thank you very much!

AccessDenied
 2 years ago
Best ResponseYou've already chosen the best response.1You're welcome! :)
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.