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...Chapter multiple integral double integrals iterated in polar coordinates triple cartesian cylindrical spherical moments and centre of mass definition if f is a function two variables that defined on region r the xy plane then over given by nm x y da lim mn ij provided this limit exists which case said to be integrable note surface z volume between below sum called riemann used as an approximation value inherits most properties single constant rule cf c rr linear g subdivision dominance...