Function inverses example 2 | Functions and their graphs | Algebra II | Khan Academy

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  • เผยแพร่เมื่อ 16 ธ.ค. 2024

ความคิดเห็น • 20

  • @iwuvvparamore
    @iwuvvparamore 12 ปีที่แล้ว +5

    Just in case you're wondering,
    a root is when the graphed line meets or intercepts
    the x-axis :)

  • @drizzzy1988
    @drizzzy1988 11 ปีที่แล้ว +8

    good shit khan

    • @calebtimes453
      @calebtimes453 7 ปีที่แล้ว

      tha docta World added by Khan = mass genocide= less people+ more room for trees= less CO2=A Green warrior.

  • @iwuvvparamore
    @iwuvvparamore 12 ปีที่แล้ว

    It's an application question.
    When you are told to graph a value of "possible real roots"
    Then you use the ≥ sign because the roots can be real in situations
    Where x is either > 0 or = to zero.
    Conversely, if the question asks you to find the value of x when there are "no possible roots", then you use x < 0 & to find 1 real root the function is x = 0.
    Conclusively,
    1)When the number of REAL roots is not specified : x ≥ 0
    2) When roots are NOT real : x < 0
    3) When there is only one root : x = 0

  • @jsd013
    @jsd013 13 ปีที่แล้ว +1

    Thanks man!

  • @KillraStealer2
    @KillraStealer2 12 ปีที่แล้ว +2

    the problem is that 2 different x gives you the same y. so the one y need to give you 2 different x if you don't constrain it.

  • @alieminemgmailcom
    @alieminemgmailcom 13 ปีที่แล้ว +2

    Can't u just expand (x+2)^2 using the identity (a+b)^2?
    Please answer soon!

  • @mtdeezy
    @mtdeezy 12 ปีที่แล้ว

    I graphed the inverse of f(x) = (x+2)^2 + 1 with no constraint and it worked just fine.

  • @Daski69
    @Daski69 10 ปีที่แล้ว +1

    one perhaps dumb question but I'd like to ask if the inverse of a function really is changing the dependent variable to the independent
    I mean if you have say
    y = 2x + 1
    x = 1/2y - 1/2
    if you graph the f(x) you get the same as if you graph the f(y), it is only when you change the y to x and x to y in the second function (the inverse) that you get the correct graph.
    Does it only become the inverse function when the switching of the y and x is done? I mean if you solve for x with respect to y you will still obviously get the same graph.
    Thanks!

    • @calebtimes453
      @calebtimes453 7 ปีที่แล้ว +1

      Daski69 After 2 years and no one answered you.....I'm not gonna bother asking a question here.

  • @iwuvvparamore
    @iwuvvparamore 12 ปีที่แล้ว

    So in this case,
    the value of x is : x < 0
    Why ?
    Because the graph does not touch the x-axis.
    It does touch the y-axis, but NOT the x-axis
    Therefore, it has No real roots and x is -2 .
    ^ Notice how the value of x ( -2 )
    corresponds to the "no real roots" rule ( x < 0 )

  • @bigstuff52
    @bigstuff52 10 ปีที่แล้ว

    Thanks for clearing up the re-naming thing.

  • @iwuvvparamore
    @iwuvvparamore 12 ปีที่แล้ว +1

    Hope this helped :D
    Oh and don't worry, this isn't that complicated.
    I'm just a Year 12 student as well hahaha

  • @Karnex1
    @Karnex1 8 ปีที่แล้ว +2

    Sorry if stupid question, but how he does that blue line y=x? It is different in every video

  • @HaiderRehman7
    @HaiderRehman7 12 ปีที่แล้ว

    please anyone explain the relation of slope with inverse function

  • @KittehsMadness
    @KittehsMadness 9 ปีที่แล้ว

    thankyou so much :D

  • @goshiluvarchie
    @goshiluvarchie 13 ปีที่แล้ว

    Someone please help? How did he find the constraint on x for the inverse function? (x >= 1)

  • @AdmatHakodesh
    @AdmatHakodesh 12 ปีที่แล้ว

    "for y is greater than or equal to 1"