Arizona State University

Then the third order partial derivative equation should be: D x 3 U=ax+by+ ∑ 0≤i< 3 , i+ j ≤ 3 c i,j D x i D y j U+h x,y . For this example, in the notation of the original theorem, the partial differential equation is third order with respect to x and would be written as follows. ................
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