Results 1 to 4 of 4

Math Help - Graphing an equation question

  1. #1
    Newbie
    Joined
    Oct 2008
    Posts
    6

    Graphing an equation question

    This is a example of graphing a Quadratic Equation in Standard form:
    By the way these are functions

    here I have: -2(x-3)+8 (x-3) is raised to the second power

    The vertex of this equation is (3,8).I cant figure out why it is not -3,8!!

    On another equation it has (x+3) +1 with (x+3) being raised to the second power. On this one the vertex is (-3,1).I cant figure why b, while being negative in both equations, gets two different results.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    A riddle wrapped in an enigma
    masters's Avatar
    Joined
    Jan 2008
    From
    Big Stone Gap, Virginia
    Posts
    2,551
    Thanks
    11
    Awards
    1
    Quote Originally Posted by mr.confused View Post
    This is a example of graphing a Quadratic Equation in Standard form:
    By the way these are functions

    here I have: -2(x-3)+8 (x-3) is raised to the second power

    The vertex of this equation is (3,8).I cant figure out why it is not -3,8!!

    On another equation it has (x+3) +1 with (x+3) being raised to the second power. On this one the vertex is (-3,1).I cant figure why b, while being negative in both equations, gets two different results.
    The vertex form for a parabola is y=a(x-h)^2+k where (h, k) is the vertex. Your equation looks like this:

    y=-2(x-^+3)^2+8

    V(3, 8)

    Notice the that h must equal +3 because there's a negative sign in the vertex form of the equation. Just remember to change the sign. That's all.

    In your second example y=(x+3)^2+1, you have a positive sign inside parentheses. The only way that can happen is if h is negative.

    y=(x-^-3)^2+1

    V(-3, 1)

    Bottom line..when you take that coordinate out of parentheses, change its sign.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Oct 2008
    Posts
    6
    Thanks for the help!! One more question, how do you guys get the graphics and the math symbols?
    Follow Math Help Forum on Facebook and Google+

  4. #4
    A riddle wrapped in an enigma
    masters's Avatar
    Joined
    Jan 2008
    From
    Big Stone Gap, Virginia
    Posts
    2,551
    Thanks
    11
    Awards
    1
    Quote Originally Posted by mr.confused View Post
    Thanks for the help!! One more question, how do you guys get the graphics and the math symbols?
    It's called Latex (pronounced Lay' tek) and it's a document markup language of which a subset is installed here.

    There a tutorial here.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Graphing a polar equation?
    Posted in the Pre-Calculus Forum
    Replies: 2
    Last Post: April 19th 2011, 04:19 PM
  2. graphing the equation y=x^2+2x+4
    Posted in the Pre-Calculus Forum
    Replies: 3
    Last Post: February 23rd 2011, 07:50 PM
  3. Is this right? Graphing an Equation
    Posted in the Algebra Forum
    Replies: 2
    Last Post: February 20th 2009, 02:41 PM
  4. Graphing an equation
    Posted in the Algebra Forum
    Replies: 3
    Last Post: April 30th 2008, 10:42 PM
  5. Graphing an equation on TI-84+ SE
    Posted in the Calculators Forum
    Replies: 3
    Last Post: December 12th 2007, 06:43 AM

Search Tags


/mathhelpforum @mathhelpforum