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!

Cannot Solve for z

  1. Jan 2, 2009 #1

    I have recently returned to education after 15 years out and I am finding that it is my basic maths that causes me the most problems. I have the following equation

    x = y (1-z)/ [tex]\pi[/tex] [tex]\sqrt{}z[/tex]

    so you know, thats pi multiplied by root z.

    and I cant solve for z, can someone rearrange this equation for me.

  2. jcsd
  3. Jan 2, 2009 #2


    User Avatar
    Science Advisor

    Do you mean
    [tex]x= \ffrac{y(1-z)}{\pi\sqrt{z}}[/itex]?
    That would be the same as [itex]\pi x\sqrt{z}= y- yz[/itex] or [itex]yz+ \pi x\sqrt{z}- y= 0[itex].

    Let [itex]u= \sqrt{z}[/itex] so that [itex]u^2= z[/itex]. Then the equation becomes [itex]yu^2+ \pi xu+ y= 0[/itex], a quadratic equation for u. That can be solved using the quadratic formula and then square u to find z.
  4. Jan 2, 2009 #3
    To me that kind of looked like:

    [tex] x = \frac{y(1-z)}{\sqrt[\pi]{z}} [/tex]

    But it could be anything.
  5. Jan 2, 2009 #4
    sorry I will try again, the equation should be

    x = \frac{y(1-z)}{\pi\sqrt{z}}

    then solve for z

    Last edited: Jan 2, 2009
  6. Jan 2, 2009 #5
    substitute [tex]z'=\sqrt{z}[/tex] and you get a quadratic eq.. Then multiply both sides by [itex]\pi z'[/itex]
  7. Jan 2, 2009 #6
    Thanks guys, I got the answer i was looking for after I made it into a quadratic.

    Thanks for your help
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Cannot Solve for z
  1. Residue of z/cos(z)? (Replies: 15)