This research aims to describe the understanding ofmathematics Tadris students of IAIN Tulungagungabout indefinite integral understanding of APOS theory. The subjects of research are six students. Each two have high, average, and low abilities. The result of the research indicated that the understanding ofmathematics Tadris (TMT) students of IAIN Tulungagung about indefinite integral understanding on actionaspect of APOS theory, high students achieve all of understanding indicators, for average students also achieve all of understanding indicators, meanwhile for low students achieve one indicator of two indicators. On process aspect, high students achieve all of understanding indicators and average students achieve all of understanding indicators too. Meanwhile low students achieve one indicator of three indicators. On objectaspect,high students achieve all of understanding indicators and average students achieve one indicator of three understanding indicators. Meanwhile for low students do not achieve all of understanding indicators. On schemeaspect, high students achieve all of understanding indicators and for average students achieve two understanding indicators. Meanwhile for low students achieve only one indicators
On the strong differentiation of the indefinite integral
