1. Limited time only! Sign up for a free 30min personal 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!

Homework Help: Integration help please [solved]

  1. Feb 7, 2010 #1
    1. The problem statement, all variables and given/known data


    [tex]\int \frac{1}{\sqrt{a^{2} + x^{2}}}[/tex]


    2. Relevant equations



    3. The attempt at a solution

    I got:


    [tex]\int \frac{1}{\sqrt{a^{2} + x^{2}}} = \sqrt{c} \ast \int \frac{1}{\sqrt{c \ast{x^{2}} + 1}} [/tex]


    [tex] \frac{1}{a^{2}} = c [/tex]

    NEVERMIND! I got it: I couldn't remember the integral of arcsin..
    so it's


    [tex] \frac{1}{a} = c [/tex]


    [tex] c \ast \int \frac{1}{\sqrt{c \ast{x^{2}} + 1}}

    = c \ast arcsin(cx) /c [/tex]
     
    Last edited: Feb 7, 2010
  2. jcsd
  3. Feb 8, 2010 #2

    This is not an arcsine integral. :redface:
    Try [tex]x=a \,\ tan(\theta)[/tex].
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook