regiondouple integration of bounded area nonrectangular

there are difference between area and volume in rectangular region and in nonrectangular region , as the tle lower limit and upper limit of integration.For rectangular region the lower and upper limit of integration as constants but for non rectangulare region one as constants and the other as functions.

there are difference between area and volume in rectangular region and in nonrectangular region , as the tle lower limit and upper limit of integration.For rectangular region the lower and upper limit of integration as constants but for non rectangulare region one as constants and the other as functions.

there are difference between area and volume in rectangular region and in nonrectangular region , as the tle lower limit and upper limit of integration.For rectangular region the lower and upper limit of integration as constants but for non rectangulare region one as constants and the other as functions.
there are difference between area and volume in rectangular region and in nonrectangular region , as the tle lower limit and upper limit of integration.For rectangular region the lower and upper limit of integration as constants but for non rectangulare region one as constants and the other as functions.
there are difference between area and volume in rectangular region and in nonrectangular region , as the tle lower limit and upper limit of integration.For rectangular region the lower and upper limit of integration as constants but for non rectangulare region one as constants and the other as functions.