# Function Help

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#1
Need some help on this:

Function f : (x, y) -> (xy, x^3)
Describe f^3 =: f . f . f

Any help is appreciated
0
1 year ago
#2
(Original post by SS__)
Need some help on this:

Function f : (x, y) -> (xy, x^3)
Describe f^3 =: f . f . f

Any help is appreciated

1
1 year ago
#3
i.e. first coordinate maps to (1st coordinate 2nd coordinate)

xy is now our new "x" and the rule is f maps "x" to "xy" i.e. (1st coordinate 2nd coordinate) as above

so under f again which is (new x) (new y)
get it?
1
#4
(Original post by RDKGames)

Not sure what's happening in that second step?
0
1 year ago
#5
the nswer is 47328653465749754169732065703465148735637856476547567430657.1
0
1 year ago
#6
(Original post by SS__)
Not sure what's happening in that second step?
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#7
(Original post by RDKGames)
What would f(xy, x^3) be? Is it ((x^4)y, x^3y^3)?
Last edited by SS__; 1 year ago
0
1 year ago
#8
(Original post by SS__)
What would f(xy, x^3) be? Is it ((x^4)y, x^3y^3)?
Yes.
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#9
(Original post by ghostwalker)
Yes.
I got (x^7y^4,x^9y^9) for fff(x,y). How do I use these to describe the function?
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1 year ago
#10
(Original post by SS__)
I got (x^7y^4,x^9y^9) for fff(x,y). How do I use these to describe the function?
First component is correct, second one isn't - you cubed the wrong part.

Other than stating what the function fff is in terms of the coordinates, I don't think there's anything you can say.
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#11
(Original post by ghostwalker)
First component is correct, second one isn't - you cubed the wrong part.

Other than stating what the function fff is in terms of the coordinates, I don't think there's anything you can say.
Oh, would it be x^12y^3 instead? And the question just says describe function f^3 so I guess that's all I can do
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1 year ago
#12
(Original post by SS__)
Oh, would it be x^12y^3 instead?
For the second component, yes.
0
1 year ago
#13
(Original post by SS__)
Oh, would it be x^12y^3 instead? And the question just says describe function f^3 so I guess that's all I can do
is one way to describe it, otherwise you can stick with their notation and say

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