Making Integrals without using mathematics own integral tool. Using rectangle formula
15523
Graphically approximating the area under a curve as a sum of rectangular regions
110697
How to unproject quadrilateral into rectangle?
18482
Can the squares with side $1/n$ be packed into a $1 \times \zeta(2)$ rectangle?
124462
Calculate integral with cantor measure
92337
Points in rectangular coordinate system - specifying coordinates as function values
92235
Explicit formula for Bernoulli numbers by using only the recurrence relation
32722
Necessity of Brackets for Integration
7944
What algorithm can be used for packing rectangles of different sizes into the smallest rectangle possible in a fairly optimal way?
130670
Solving Integrals
31587
Finding a difficult integral
62201
How to calculate this integral using FTC
115090
Alternative definition of hyperbolic cosine without relying on exponential function
124401
How to evaluate $\int_0^{2\pi}\frac{1}{(1+a\cos {\theta})^2}\,d\theta$ without contour integration?
128716
Intuitive/direct proof that a rectangle partitioned into rectangles each with at least one integer side must itself have an integer side
81328
How to find the dimensions of a rectangle given a) the area and the diagonal or b) the perimeter and the diagonal
38139
Solid volume using double integral
158494
Properties of special rectangle (measure)