Quantcast

Got Homework?

Connect with other students for help. It's a free community.

  • across
    MIT Grad Student
    Online now
  • laura*
    Helped 1,000 students
    Online now
  • Hero
    College Math Guru
    Online now

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

kaisan Group Title

verify: sin(x+y)-sin(x-y)=2cosxsiny

  • 2 years ago
  • 2 years ago

  • This Question is Closed
  1. malexander Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    cos(x+y)=cosxacosy-sinxsiny cos(x-y)=cosxcosy+sinxsiny addition produces 2cosxcosy

    • 2 years ago
  2. lgbasallote Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    take the left hand side...do you know the formula for sin(x+y) and sin(x-y)?

    • 2 years ago
  3. malexander Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    Its an identity.

    • 2 years ago
  4. kaisan Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    i think so but i'm not sure

    • 2 years ago
  5. lgbasallote Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    sin(x+y) = sinxcosy + sinycosx sin(x-y) = sinxcosy - sinycosx can you do it from here?

    • 2 years ago
  6. kaisan Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    it looks familiar but i can't figure it out. is it one of the cosine identities?

    • 2 years ago
  7. lgbasallote Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    no...you substitute those into your problem sin(x+y) - sin (x-y) = sinxcosy + cosxsiny - (sinxcosy - cosxsiny)

    • 2 years ago
  8. kaisan Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    i'm still confused

    • 2 years ago
  9. lgbasallote Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    with what?

    • 2 years ago
  10. kaisan Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    how to do all of this in general

    • 2 years ago
  11. lgbasallote Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    basically you memorize the identities...

    • 2 years ago
  12. lgbasallote Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    i did not do anything fancy...all i did was substitute identities

    • 2 years ago
  13. kaisan Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    oh ok

    • 2 years ago
  14. lgbasallote Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    so regarding this problem...you're good?

    • 2 years ago
  15. kaisan Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    not really...

    • 2 years ago
  16. lgbasallote Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    sinxcosy + cosxsiny - (sinxcosy - cosxsiny) sinxcosy = cosxsiny - sinxcosy + cosxsiny

    • 2 years ago
  17. lgbasallote Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    that's a + not an =

    • 2 years ago
  18. kaisan Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    i don't understand what you did

    • 2 years ago
  19. lgbasallote Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    i distributed the minus sign

    • 2 years ago
  20. kaisan Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    oh ok i see

    • 2 years ago
  21. lgbasallote Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    so you're good now?

    • 2 years ago
  22. kaisan Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    yes thanks ^^

    • 2 years ago
    • Attachments:

See more questions >>>

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
  • 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.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.