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Expert: Alon Mandes - 8/5/2008


Question
Looking for the solution to d/dx ln((x^2+y^2)^(1/2))/a

Can you help?

Answer
If y is independent of x then dy/dx=0.If not then dy/dx=y'
{Ln[f(x)]}'=[1/f(x,y)]*[df(x,y)/dx].
f(x,y)=(1/a)[x^2+y^2]^0.5
So df(x,y)/dx=(1/a)*{ 1/[x^2+y^2]^0.5 }* {2x+2yy'}. Note that if y
is independent of x then y'=0.
d/dx {Ln[f(x,y)]} = [1/f(x,y)]*(1/a)*{ 1/[x^2+y^2]^0.5 }* {2x+2yy'}
--> d/dx {Ln[f(x,y)]}=[2x+2yy']/[x^2+y^2].

Alon.  

Calculus

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Alon Mandes

Expertise

Kind of questions I can answer : Limits, Derivatives, Integration, Implicit functions, continuousity, differentiation ,Extremum problems, Lagrange multipliers, Gradients, Surface integrals, Multi variables functions ,Multi variables Integrals,Complex variables ,Complex functions, Curves, Trajectory integrals & Vector analyse,Divergence,Rotor & word problems. Kind of question I can't answer : Economics,Combinatorics,infinite series & convergence ,Statistics & Probabilities .

Experience

1. I'm a team member of mathnerds (math site for answering questions) 2. I'm a team member in the Student's Union of the Technion, helping students who have problems in mathematics. 3. 2 years of experience as a math teacher in college. 4. I give free homework help for high school students in Mathematics & Physics. 5. I teach part time in collage the subjects : "Digital Signal Processing" , "Random Signals & Noise" , "Complex Functions".

Organizations
Hi-Tech company : GSM4VOIP ; job possition : Algorythm developer.

Education/Credentials
M.A in Mathematics & Bs.c in Electronics.

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