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SNOOTCHIEBOOCHEE

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## Homework Statement

i)Prove that f: [tex]R^2\rightarrow R[/tex]

f(x,y)= [tex]\frac{x^4 + y^4}{(x^2+y^2)^\alpha}[/tex] (x,y) =/= (0,0)

f(x,y)= 0 (x,y)=(0,0)

is differentiable on [tex]R^2[/tex] for [tex]\alpha[/tex]<3/2

## Homework Equations

let f be a vector function from n variable sto m variables

i) f is said to be diffable at a point a (element) R^n iff there is an open set V containing a such that f: [tex]R\rightarrow R^m[/tex] and there is a T (element) L(R^n;R^m) such that the function

[tex]\epsilon[/tex](h) := f(a+h)-f(a)-T(h) satisfies [tex]\epsilon[/tex](h)/||h|| ---> 0 as h--->0

ii) f is said to be differentiable on a set E iff E is not empty and f is diffable at every point in E

## The Attempt at a Solution

I actually have no clue how to do this problem. I had my wisdom teeth pulled the day he covered this in lecture. please HALP MEH!