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: Restricting Domain and Range in broken conics

  1. Mar 22, 2009 #1
    1. The problem statement, all variables and given/known data
    How do you know whether you restrict the domain or range with a horizontal ellipse ?

    2. Relevant equations
    x^2/49 +y^2/10=1

    3. The attempt at a solution
  2. jcsd
  3. Mar 22, 2009 #2


    User Avatar
    Science Advisor

    Since y2 is never negative, x will be largest when y= 0. And when y= 0, [itex]x^2/49= 1[/itex], [itex]x^2= 49[/itex], [itex]x= \pm 7[/itex]. [itex]-7\le x\le 7[/itex]. Similarly, if x= 0 [itex]y^2/10= 1[/itex] so [itex]y= \pm\sqrt{10}[/itex]. If x is not zero, [itex]y^2[/itex] is smaller than 10 so [itex]-\sqrt{10}\le y\le\sqrt{10}[/itex].
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook