Riemann sum
Mathematical term for approximating the area under a curve by partitioning it into small rectangles or other shapes.
Find the area under the curve using Riemann sums.
積分 is the general term for integration, while 区分求積法 specifically refers to the Riemann sum method of approximating integrals.
Compound of 区分 (division, partition), 求 (seek, find), 積 (accumulation, product), and 法 (method). The term is a direct translation of the mathematical concept 'Riemann sum'.