1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Derivative. arctan(x - sqrt(1+x^2))

  1. Oct 9, 2008 #1
    1. The problem statement, all variables and given/known data

    Find the derivative of the function. Simplify where possible.
    arctan(x - sqrt(1+x2))

    2. Relevant equations

    Chain rule

    3. The attempt at a solution

    let u = x - sqrt(1+x2)

    y = tan-1(u)

    dy/du = 1/(1+ u2)
    sub in u.
    dy/du = 1/1 + (x - sqrt(1+x2))2


    du/dx = 1 - 1/2 (1+x2)-1/2 (2x)

    dy/dx = (1/1 + (x - sqrt(1+x2))2) (1 - 1/2 (1+x2)-1/2 (2x))


    I always seem to forget 1 term and I am basically wondering if my method here is correct.
     
  2. jcsd
  3. Oct 9, 2008 #2

    Redbelly98

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper

    Looks right to me. It would be good to include another pair of parentheses in the first term:

    dy/dx = (1/(1 + (x - sqrt(1+x2))2)) (1 - 1/2 (1+x2)-1/2 (2x))
     
  4. Oct 9, 2008 #3
    Thank you.

    I am new to the forums here and I must say they are great!
     
  5. Oct 9, 2008 #4

    Redbelly98

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper

    You're welcome, and welcome to PF.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Derivative. arctan(x - sqrt(1+x^2))
Loading...