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: Solving system of equations

  1. Feb 22, 2007 #1
    1. The problem statement, all variables and given/known data

    y = 5x^2 + 1
    x^2 + 6y2 = 21

    2. Relevant equations

    quadratic formula

    3. The attempt at a solution

    I am not quite sure how to solve algebraically...
    My parabola is this
    0 1
    1 6

    0 | 1.87
    4.5 | 0

    How can I manipulate the formula to solve the points which the ellipse crosses the parabola
  2. jcsd
  3. Feb 22, 2007 #2
    Try solvng for x^2 and plugging that into one equation. Then plug in each y solution to get 2 corresponding x solutions. At the end, check to make sure all your answers work in the original equations
  4. Feb 22, 2007 #3
    Not sure what you mean... =/
  5. Feb 23, 2007 #4


    User Avatar
    Staff Emeritus
    Science Advisor

    Rearrange your second equation to give [itex]x^2=21-6y^2[/itex], then substitute this into the first equation [itex]y=5x^2+1[/itex]. You will obtain a quadratic equation in y which you should be able to solve.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook