Math question

This is a discussion on Math question within the A Brief History of Cprogramming.com forums, part of the Community Boards category; Er... verify something for me guys; Is the derivative of Code: sin(cos(x)) equal to Code: -cos(cos(x))sin(x)...

  1. #1
    BMJ
    BMJ is offline
    Banal internet user BMJ's Avatar
    Join Date
    Aug 2002
    Location
    Chicagoland
    Posts
    1,380

    Question Math question

    Er... verify something for me guys; Is the derivative of
    Code:
    sin(cos(x))
    equal to
    Code:
    -cos(cos(x))sin(x)

  2. #2
    Mayor of Awesometown Govtcheez's Avatar
    Join Date
    Aug 2001
    Location
    MI
    Posts
    8,825
    That's not what I got - I got
    sin(-sin(x)) * cos(cos(x))

    I could be wrong, though.

  3. #3
    BMJ
    BMJ is offline
    Banal internet user BMJ's Avatar
    Join Date
    Aug 2002
    Location
    Chicagoland
    Posts
    1,380
    Where did that extra sine come from?

  4. #4
    Mayor of Awesometown Govtcheez's Avatar
    Join Date
    Aug 2001
    Location
    MI
    Posts
    8,825
    Chain rule.

  5. #5
    BMJ
    BMJ is offline
    Banal internet user BMJ's Avatar
    Join Date
    Aug 2002
    Location
    Chicagoland
    Posts
    1,380
    Code:
    f(x) = sin(cos(x))
    Code:
    f'(x) = cos(cos(x)) * (-sin(x)) * (1)
    Right?

  6. #6
    Mayor of Awesometown Govtcheez's Avatar
    Join Date
    Aug 2001
    Location
    MI
    Posts
    8,825
    Um... Maybe. Like I said, I could be (and likely am) wrong...

    Heh, 3 years of calc, and I can't remember a damn thing. Thank you, beer!

  7. #7
    Mayor of Awesometown Govtcheez's Avatar
    Join Date
    Aug 2001
    Location
    MI
    Posts
    8,825
    The answer I got from people that are better at this than me was -sin(x) * cos(cos(x)), so the same thing that you got.

    Guess it's time to dig out that calc book again.

  8. #8
    BMJ
    BMJ is offline
    Banal internet user BMJ's Avatar
    Join Date
    Aug 2002
    Location
    Chicagoland
    Posts
    1,380
    I just want to make sure I am remembering this stuff right so that I don't mess my entire week up as I go back trying to figure out what's wrong only to find it's this stuff

  9. #9
    BMJ
    BMJ is offline
    Banal internet user BMJ's Avatar
    Join Date
    Aug 2002
    Location
    Chicagoland
    Posts
    1,380
    Ok thanks Govtcheez!

  10. #10
    5|-|1+|-|34|) ober's Avatar
    Join Date
    Aug 2001
    Posts
    4,429
    working on... finding... Maple...

    ok... I can't locate a free download of it anymore, but it's useful for checking your derivatives/integrals... sorry... you could look around for a copy of it tho.
    EntropySink. You know you have to click it.

  11. #11
    BMJ
    BMJ is offline
    Banal internet user BMJ's Avatar
    Join Date
    Aug 2002
    Location
    Chicagoland
    Posts
    1,380
    I've never heard of it... does it work well?

  12. #12
    Mayor of Awesometown Govtcheez's Avatar
    Join Date
    Aug 2001
    Location
    MI
    Posts
    8,825
    ONce you figure it out, it's helpful. I never got the hang of it, though.

  13. #13
    BMJ
    BMJ is offline
    Banal internet user BMJ's Avatar
    Join Date
    Aug 2002
    Location
    Chicagoland
    Posts
    1,380
    Hmmm... maybe I should write something to calculate derivative expressions like a TI-89 or Maple does

  14. #14
    5|-|1+|-|34|) ober's Avatar
    Join Date
    Aug 2001
    Posts
    4,429
    yeah, there's definately a learning curve, but when you can type in an equation and it spits out what you want.... you just can't beat it.
    EntropySink. You know you have to click it.

  15. #15
    back? dbaryl's Avatar
    Join Date
    Oct 2001
    Posts
    597
    um... what about my TI-92?

Page 1 of 2 12 LastLast
Popular pages Recent additions subscribe to a feed

Similar Threads

  1. another exercise question
    By luigi40 in forum C# Programming
    Replies: 3
    Last Post: 11-28-2005, 02:52 PM
  2. opengl DC question
    By SAMSAM in forum Game Programming
    Replies: 6
    Last Post: 02-26-2003, 08:22 PM
  3. More a math question than an algorithm
    By Gustaff in forum C Programming
    Replies: 1
    Last Post: 01-28-2003, 12:10 PM
  4. Stupid Math Question....really stupid
    By ToLazytoSignIn in forum A Brief History of Cprogramming.com
    Replies: 9
    Last Post: 01-16-2003, 06:36 PM
  5. Math Question
    By DarkEldar77 in forum C++ Programming
    Replies: 2
    Last Post: 09-17-2001, 12:52 PM

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21