A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

anonymous

  • 5 years ago

Can someone please explain how to use the half-angle formula to solve sin Pi/8?

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

    hi jake are yo there? do yo know the formula for half angle ?

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

    sin(x/2)=sqrt((1-cosx)/2)

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

    i think it is sin alpha/2=the square root of 1-cos alpha/2. it looks really weird having to type it out

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

    so alpha is just x. that makes more sense

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

    yes ..ok you can find x here by eqating x/2=pi/8

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

    i got x=.7853...

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

    ok use that for the right hand side

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

    I'm sorry I don't know what the next step is..

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

    ok here it is ill give you it more better

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

    sin((pi/4*2)=sqrt(1-cos(pi/4)/2) =sqrt((1-(sqrt2)/2))2 =sqrt((2-sqrt2))/4 =sqrt(.1464466) =.38268

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

    so pi/4 became your x here

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

    does it make sense ?

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

    yes that is making sense. i'm just trying to redo it on paper to see if i can get the same answer. Thank you very much

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

    ok wc jake

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

    you got it....good luck

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

    Thanks!

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

    k,yo have any more question or anymore prob i can help u maybe?

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

    are you not busy?

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

    not really lol

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

    haha well i'm in pre cal obviously and not very good at it. i have this problem: if sin theta=3/5, and tan theta<0 then in what quadrant is the point (cos theta, sin theta)?

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

    ok here we can put theta =x...therefore tanx=sinx/cosx so x=3/5 its in the first quadrant..but tanx is negative) so it is obvius that sin 3/5 is in the first quadrant and the cosx is in the 3rd quadrant

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

    cos x in the third quadrant is negative sign

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

    tanx <0 means tanx is a negatinve sign

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

    Wow thank you for your help mark

  25. 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.