3.4.8. Calculation of volumes using double integral

Volume V of a body bounded by a surface z = f ( x, y ). , where f ( x, y ) is a non-negative function, the plane z = 0 and a cylindrical surface, the guide for which is the border of region D , and forming parallel to the axis OZ , is equal to the double integral of the function f ( x, y ) over region D :

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