A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

anonymous

  • 5 years ago

Find sin (x+y), assuming that sin x= -2/3, cos y=1/4 and both x and y are in quadrant IV.

  • This Question is Closed
  1. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    sin(x+y)=sinxcosy+cosysinx

  2. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    are you familiar with this identity?

  3. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    no

  4. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    i have to look at my notes

  5. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    do you know how to find cos(x) if you are given sin(x)? because you need that too.

  6. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    sin x=1/cos x

  7. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    This is incorrect I think you are mistaking it with sec(x)=1/cos (x)

  8. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    oh, you're right

  9. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Okay, so we know this identity sin(x+y)=sin(x)cos(y)+cos(y)sin(x) now we have to plug in what we know

  10. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    You know sin(x),cos(y) you don't know sin(y),cos(x)

  11. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    i have no idea what to do

  12. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    So you need to find what you don't know are you familiar with soh-cah-toa

  13. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    a bit, but I don't even know how you got sin (x+y)=sin (x)cos(y)+cos(y)sin(x)

  14. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    this is identity, you just need to know that

  15. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    ok, I see it in my notes under cosine of a sum or difference

  16. Not the answer you are looking for?
    Search for more explanations.

    • Attachments:

Ask your own question

Sign Up
Find more explanations on OpenStudy
Privacy Policy

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.