Does somebody knows how to derive this?

Last Monday my Intro to Material class got a new lecturer.

And we learnt about Diffusion.

Difussion is a process which a matter is transported through

another matter.

She gave us a first assignment and we got this one type of

question that nobody in my class really know how to solve it.

I don’t know from the ladies side,maybe they already

got the solution.However, I’m still searching for the way how to

solve it. The question is:

Derive this Fick’s second law from ;

to the equation below;

The equation above is the common equation used to solve

problems in this Diffusion chapter.

so, do you know how to derive the fick’s second law?

Or does anyone, your friends , family members

who learnt materials has any idea about this?

I believe some of you might know how to derive that..

Willing to share it with me?