Function inverse example 1 | Functions and their graphs | Algebra II | Khan Academy

Function Inverse Example 1

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[Vincstylez]

Like a good neighbor kahnacademy is there!

[kellyyates]

let say you were asked this;
find the inverse of f(x)=(x+3)^2-9
would you have to foil first or do the inverse part first ?

[jgphonecall]

i like how your videos are kinda philosophical, which gives me a better understanding. i owe you some money.

[DOGGEATDOGG]

@khanacademy will this apply to calculus too?

[ryanlgy]

Can you be my calculator for my test tomorrow?

[jaybandl]

You can't just "rename it as a function of x".
The original function sets the relationship, and changes cannot be arbitrary.

Swapping the variables is correct, but this is actually the "inversion part",
and the '-1' notation should not appear until the variables are swapped.

This swapping of the variables flips the plot across the diagonal x=y,
the intention of an inverted (inverse) function, since it can combine
with the original function to cancel back to the line x=y .
MIT is not right.

[hollowfocus]

thanks a lot for posting this helpful video:)

[Joe-njjr]

For the first example, why did he multiply both sides by - instead of dividing?

[devinnair]

How do you know where the graph cuts the x axis?

[werewolfpudding]

I was following until the end when Y magically turned into X for the inverse function written out. Can you please explain how thats possible? thanks for making your videos.

[Daski]

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!

[imeicshuro]

please use a brighter colour so that we see the notes better☺

[HaiderRehman]

Please anyone explain that how slopes are drawn on the coordinate axis?

[neumans]

Great video! Which program did you use to make this video?

[paulceltics]

there are some voice issues of these videos

[joshuayoon]

is sal a girl name?? bc his/her name is sal

[SpinyNormanDinsdale]

@jjaysober NOOO! He should be at TED talks!

[MrDevin]

Damn i wish i had the power to spawn you whenever!

[Kcvee]

@MrDevin666 LOL, id spawn him at my exam