Question

(1 point) find ∬rf(x,y)da∬rf(x,y)da where f(x,y)=xf(x,y)=x and r=[1,6]×[4,5]r=[1,6]×[4,5].

Answer 1

$\displaystyle\iint_Rf(x,y)\,\mathrm dA=\int_{y=4}^{y=5}\int_{x=1}^{x=6}x\,\mathrm dx\,\mathrm dy=\int_{x=1}^{x=6}x\,\mathrm dx=\frac{35}2$