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

Hannah_Ahn Group Title

prove the identity csc theta over tan theta + cot theta = cos theta

  • 2 years ago
  • 2 years ago

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

    \[\frac{ \frac{1}{sin {\theta}}}{tan{\theta}}+\frac{1}{tan{\theta}}=cos{\theta}\]

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

    I am sorry, how did that happen?

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

    Sorry I will write it up first and post it with steps. Just a moment

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

    Sweet, thanks!

    • 2 years ago
  5. Yifan12879 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    does it mean that (1/sin x)^2+(1/sin x)=1?

    • 2 years ago
  6. Yifan12879 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    if you divide the cos theta from both sides

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

    Yes correct

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

    I still would appreciate to see the steps plz :s

    • 2 years ago
  9. Yifan12879 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    but why? let x=pi/6 then 4+2=1??

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

    yes I'm having that issue too. Are you sure it's written down right?

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

    \[\csc \theta \over \tan \theta +\cot \theta\] = [\cos \theta\]

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

    I see now, next time put the tan theta + cot theta in brackets to make it clearer.

    • 2 years ago
  13. Yifan12879 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    multiply the LHS by sinx cosx

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

    gotcha. sorry about that.

    • 2 years ago
  15. Yifan12879 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    i mean csc x /(tan x + cot x)= cscx sinx cosx / (tanx sinx cosx+cotx sinx cosx)=cosx/(sin^2 x+cos^2 x)=cosx

    • 2 years ago
  16. Yifan12879 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    im sorry it should be theta...

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

    why did you multiply each sides by sinx cosx? how could u tell?

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

    \[\frac{1/sin{\theta}}{tan{\theta}+1/tan{\theta}}=cos{\theta}\]\[1/sin{\theta}=tan{\theta}cos{\theta}+cos{\theta}/tan{\theta}\]\[1/sin{\theta}=sin{\theta}+cos^2{\theta}/sin{\theta}\]\[1/sin{\theta}=sin^2{\theta}/sin{\theta}+cos^2{\theta}/sin{\theta}\]\[1/sin{\theta}=1/sin{\theta}\]\[1=1\]

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

    Here's a different way to go about it :)

    • 2 years ago
  20. Yifan12879 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    because there are sinx cosx in the denominator

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

    my teacher doesn't let me combite the left side and the right side.. in this case i would need to make the left side cos theta. :S

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

    zed; yur way is something to think about, and it's cool. yet i won't b able to use your method

    • 2 years ago
  23. Yifan12879 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    @Zed you shouldnt give out a prove like this, you should write LHS=...=....=...=RHS

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

    yifian; i don't really get how you got there.. :(

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

    i can't figure it out

    • 2 years ago
  26. Yifan12879 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    which step?

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

    is there other way to do it?

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

    Thanks Yifan, I haven't done proof in a long time. \[LHS = \frac{1/sinx}{sinx/cosx+cosx/sinx}\] \[=\frac{1/sinx}{(sin^2x+cos^2x)/sinxcosx}\]\[=\frac{1/sinx}{1/sinxcosx}\]\[=\frac{1}{cosx}\]\[=RHS\]

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

    sorry that second last line was supposed to be cosx

    • 2 years ago
  30. Yifan12879 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    yeah that is a good prove except that you substitute theta for x..

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

    yeah i got tired of writing theta out

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

    thanks Yifan

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

    1 over cos x isn't same as cos x

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

    It was a typo

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

    i got that too.

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

    well thanks for your time :)

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

    i still don't get it . for some reason, im very confused. i will ask my teacher and I will let you know if there is a simpler way to do it if you are interested :P g'nite.

    • 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.