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Hokiehigh
Multicalculus problem. let f(x,y)=(x-y)/(x+y), find the directions u and the values of Duf(-1/2,3/2) for which a) Duf(-1/2,3/2) =is largest b) Duf(-1/2,3/2) = 0 c) Duf(-1/2,3/2)=1
directional derivative
Df=(2y/((x+y)^2,-2x/(x+y)^2) (2y/((x+y)^2,-2x/(x+y)^2).(-1/2,3/2)
(2y/((x+y)^2,-2x/(x+y)^2).(-1/2sqrt2,3/2sqrt2)
I think I see what your saying. Thank you
sorry (2y/((x+y)^2,-2x/(x+y)^2).(-1/sqrt10,3/2sqrt10)
(2y/((x+y)^2,-2x/(x+y)^2).(-1/sqrt10,3/sqrt10)
-2/sqrt10(1/(x+y)) I guess this is the answer..
I just looked at this web site http://tutorial.math.lamar.edu/Classes/CalcIII/DirectionalDeriv.aspx#PD_DirectDeriv_Ex2a