9367 Q63
Posted: Wed Dec 21, 2011 4:25 am
Let R be the circular region of the xy-plane with center at the origin and radius 2.
Then $$\int\int_R{e^{-(x^2+y^2)}dx dy=$$
I fell into the trap and answered:
$$=\int\int e^{-4}dA=4\pi e^{-4}$$
May I know what is wrong with the above approach, and how do we get the correct answer?
Thanks a lot.
Then $$\int\int_R{e^{-(x^2+y^2)}dx dy=$$
I fell into the trap and answered:
$$=\int\int e^{-4}dA=4\pi e^{-4}$$
May I know what is wrong with the above approach, and how do we get the correct answer?
Thanks a lot.