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: Probably very easy - Domain/range on parametric->cartesian equation

  1. Dec 11, 2012 #1
    1. The problem statement, all variables and given/known data
    Convert x=tant, y=sect on ∏/2<t<∏ to rectangular system and graph. Show domain, rnage, and orientation

    I use sec2=tan2+1 -> y2-x2=1 which is a hyperbolic function with the graph http://www.wolframalpha.com/input/?i=y^2-x^2%3D1

    I know that the graph is only in the 3rd quadrant but I'm not sure why - also, I'm not sure what the domain/range is. I think the domain (valid X's) are -∞ to 0, and range would be -∞ to -1 based on the graph being in the third quadrnat only? How would I get that the graph is only in the 3rd quadrant (probably something to do with the boundaries), and are the domain/range correct
    Last edited: Dec 11, 2012
  2. jcsd
  3. Dec 11, 2012 #2
    Bump if I may, my test is in 30 minutes :)
  4. Dec 11, 2012 #3


    Staff: Mentor

    On the interval [##\pi/2, \pi##] x < 0 and y ≤ -1. Sketch graphs of x = tan(t) and y = sec(t) to see this. These graphs should give you some insight into the values of x and y.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook