Mass of $ A := { x in R^2 | x<y , y1/x }$












1












$begingroup$


How does one calculate the Lebesgue Measure of the above set?



I tried the following:



$ lambda^2(A) = int_{R^2} 1_A d(lambda^2(x,y)) = int_Rint_x^2 1_{ {1/x < y} } dlambda(y)dlambda(x)$



but then I have no idea how to reformulate the inequality $1/x < y $.










share|cite|improve this question











$endgroup$












  • $begingroup$
    Your set contains ${(x,y) in mathbb{R}^2 : x < 0, 0 < y < 2}$, which has infinite measure. Therefore there is either a mistake in the question or the answer is obviously $infty$.
    $endgroup$
    – Klaus
    Jan 30 at 13:31










  • $begingroup$
    Perhaps the OP meant to include an additional constraint - maybe something like $x > 0$?
    $endgroup$
    – Jordan Green
    Jan 30 at 17:01
















1












$begingroup$


How does one calculate the Lebesgue Measure of the above set?



I tried the following:



$ lambda^2(A) = int_{R^2} 1_A d(lambda^2(x,y)) = int_Rint_x^2 1_{ {1/x < y} } dlambda(y)dlambda(x)$



but then I have no idea how to reformulate the inequality $1/x < y $.










share|cite|improve this question











$endgroup$












  • $begingroup$
    Your set contains ${(x,y) in mathbb{R}^2 : x < 0, 0 < y < 2}$, which has infinite measure. Therefore there is either a mistake in the question or the answer is obviously $infty$.
    $endgroup$
    – Klaus
    Jan 30 at 13:31










  • $begingroup$
    Perhaps the OP meant to include an additional constraint - maybe something like $x > 0$?
    $endgroup$
    – Jordan Green
    Jan 30 at 17:01














1












1








1





$begingroup$


How does one calculate the Lebesgue Measure of the above set?



I tried the following:



$ lambda^2(A) = int_{R^2} 1_A d(lambda^2(x,y)) = int_Rint_x^2 1_{ {1/x < y} } dlambda(y)dlambda(x)$



but then I have no idea how to reformulate the inequality $1/x < y $.










share|cite|improve this question











$endgroup$




How does one calculate the Lebesgue Measure of the above set?



I tried the following:



$ lambda^2(A) = int_{R^2} 1_A d(lambda^2(x,y)) = int_Rint_x^2 1_{ {1/x < y} } dlambda(y)dlambda(x)$



but then I have no idea how to reformulate the inequality $1/x < y $.







integration measure-theory lebesgue-measure






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Jan 30 at 13:29







Slyder

















asked Jan 30 at 13:23









SlyderSlyder

316




316












  • $begingroup$
    Your set contains ${(x,y) in mathbb{R}^2 : x < 0, 0 < y < 2}$, which has infinite measure. Therefore there is either a mistake in the question or the answer is obviously $infty$.
    $endgroup$
    – Klaus
    Jan 30 at 13:31










  • $begingroup$
    Perhaps the OP meant to include an additional constraint - maybe something like $x > 0$?
    $endgroup$
    – Jordan Green
    Jan 30 at 17:01


















  • $begingroup$
    Your set contains ${(x,y) in mathbb{R}^2 : x < 0, 0 < y < 2}$, which has infinite measure. Therefore there is either a mistake in the question or the answer is obviously $infty$.
    $endgroup$
    – Klaus
    Jan 30 at 13:31










  • $begingroup$
    Perhaps the OP meant to include an additional constraint - maybe something like $x > 0$?
    $endgroup$
    – Jordan Green
    Jan 30 at 17:01
















$begingroup$
Your set contains ${(x,y) in mathbb{R}^2 : x < 0, 0 < y < 2}$, which has infinite measure. Therefore there is either a mistake in the question or the answer is obviously $infty$.
$endgroup$
– Klaus
Jan 30 at 13:31




$begingroup$
Your set contains ${(x,y) in mathbb{R}^2 : x < 0, 0 < y < 2}$, which has infinite measure. Therefore there is either a mistake in the question or the answer is obviously $infty$.
$endgroup$
– Klaus
Jan 30 at 13:31












$begingroup$
Perhaps the OP meant to include an additional constraint - maybe something like $x > 0$?
$endgroup$
– Jordan Green
Jan 30 at 17:01




$begingroup$
Perhaps the OP meant to include an additional constraint - maybe something like $x > 0$?
$endgroup$
– Jordan Green
Jan 30 at 17:01










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