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: Am i right?

  1. Mar 23, 2007 #1
    can you quickly see if i'm right, because im not positive ive done it correctly...

    thnx

    1. The problem statement, all variables and given/known data

    The equation of a curve is [tex]y=f(x)[/tex], where [tex]f(x) = x^2 - 6x + 14[/tex].

    Find the coordinates of the minimum point , [tex]M[/tex], of the curve

    2. Relevant equations



    3. The attempt at a solution

    I completed the square to get

    [tex]y=(x-3)^2 + 5[/tex]

    then i used my knowledge of transformation of function to work out the answer is [tex](3,5)[/tex]

    however, im not sure i did it right, im pretty sure the y-coordinate is right, but the x-coordinate may be wrong...

    can you help?
     
  2. jcsd
  3. Mar 23, 2007 #2
    You are right.
     
  4. Mar 23, 2007 #3
    yay! thnx buddy :D
     
  5. Mar 23, 2007 #4

    HallsofIvy

    User Avatar
    Science Advisor

    Look at the reasoning: if x= 3, then obviously y= (3-3)2+ 5= 0+ 5= 5. If x is any number other than 3, (x-3)2 is positive so (x-3)2+ 5 is larger than 5.
     
  6. Mar 23, 2007 #5
    o rite thnx for that, i never realised why it worked out the way it did :D

    cheers lol

    i just went on my transformation of function graph knowledge without understanding it hehe, silly teachers
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook