1. let r be the equilateral in the xy plane with vertices (1,0), (4,0), (0,1) and (0,4) evaluate the double integral 1/(x+y) da with the substation x=u-uv y=uv

Step-by-step explanation:

Given that R is a treapezium with given vertices in the xy plane with side 3 units.

Substitution is

Hence dx dy = ududv

Integrand =

Limits now we have to change

We see from the vertices the line x+y changes from 1 to 4, i.e. 1<u<4 and

we get so v varies from 0 to 1

The given integral

=

x equals 1

step-by-step explanation:

f(4)=f(×)

x=1

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