Results 1 to 3 of 3

Math Help - Hey everyone, I'm Wu =) Nice to meet you

  1. #1
    Newbie
    Joined
    Jul 2012
    From
    China
    Posts
    2

    Wink Hey everyone, I'm Wu =) Nice to meet you

    Currently studying math, sorry if my english is bad.

    I am Wu Zhong Lan.
    I am 18 years old =)

    I am puzzled with some questions.

    Questions:
    3 equations xy = 1 x^2 + y^2 = 1 x^2 + y^2 = 4

    In surd form, show the 4 intersections of the last graphs with the first.
    I am puzzled to where to start :S

    Thank you =)
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor

    Joined
    Apr 2005
    Posts
    14,973
    Thanks
    1121

    Re: Hey everyone, I'm Wu =) Nice to meet you

    Well, an obvious start would be to draw the graphs since that is what is asked. Or you could solve as pairs of equations. The graphs of xy= 1 and x^2+ y^2= 1 intersect when both equations are satisfied. From xy= 1, y= 1/x so the second equation is x^2+ (\frac{1}{x})^2= x^2+ \frac{1}{x^2}= 1. Multiplying both sides of that by x^2 gives x^4+ 1= x^2. Let u= x^2 and that becomes u^2+ 1= u or u^2- u+ 1= 0. Can you solve that quadratic equation?

    The graphs of xy= 1 and x^2+ y^2= 4 intersect where both equations are satisfied. Do the same as above.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Jul 2012
    From
    China
    Posts
    2

    Re: Hey everyone, I'm Wu =) Nice to meet you

    Ahhhh yes yes, I see. thank you a lot! =)
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Nice to Meet you all! :)
    Posted in the New Users Forum
    Replies: 0
    Last Post: July 11th 2012, 07:27 AM
  2. Replies: 0
    Last Post: May 17th 2012, 12:31 PM
  3. Nice to meet you!
    Posted in the New Users Forum
    Replies: 1
    Last Post: March 26th 2012, 06:27 AM
  4. When Will Two Men Meet?
    Posted in the Pre-Calculus Forum
    Replies: 2
    Last Post: December 7th 2008, 09:07 AM
  5. Meet the demand D
    Posted in the Pre-Calculus Forum
    Replies: 0
    Last Post: July 20th 2006, 07:52 AM

Search Tags


/mathhelpforum @mathhelpforum