What is the limit of (x^3-y^3)/(x^2+y^2) as (x,y)-->(0,0)
We have to find the value of lim x,y-->0 [(x^3-y^3)/(x^2+y^2)]
We cannot substitute x and y with 0 in the expression as that would yield 0/0 which is indeterminate.
We see that the expression is defined for all values of (x,y) except (0,0), so we approach (0,0) along y = mx
lim x,y-->0 [(x^3-y^3)/(x^2+y^2)]
=> lim x-->0 [(x^3- m^3*x^3)/(x^2+m^2*x^2)]
=> lim x-->0 [(x^3(1 - m^3))/(x^2(1+m^2))]
=> lim x-->0 [(x(1 - m^3))/(1+m^2)]
Now substituting x = 0
=> 0*(1 - m^3) / (1 + m^2)
Therefore the required value of the limit is 0.
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