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: Is my book making an algebra error?

  1. Oct 27, 2012 #1
    Not sure if this is a notation error or an algebra or if I am wrong , but my book presents a system of equations and I cannot get it into the form which it is presented

    [itex]\tau _b = \left(1 + \frac{\Phi _b}{c^2}\right)\text{ }\text{$\Delta $t}[/itex]

    [itex]\tau _a = \left(1 + \frac{\Phi _a}{c^2}\right)\text{ }\text{$\Delta $t}[/itex]

    [itex]\tau _b = \left(1 + \frac{\Phi _{b-}\Phi _a}{c^2}\right)\text{ }\tau _a [/itex]

    Just wondering if I am missing something obvious here or if they are performing black magic. I tried subbing in for delta t and then doing long division but my answer was slightly different from their form.
  2. jcsd
  3. Oct 27, 2012 #2


    User Avatar
    Homework Helper
    Gold Member
    2017 Award

    Could it be that they are making an approximation under the assumption that ##\frac{\Phi_a}{c^2}## is much smaller than 1?
  4. Oct 27, 2012 #3
    Ahh I suppose that you are probably right.. thank you.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook