Riemann Integral

Overview


The Riemann integral was one of the first and simplest integrals to be defined. An integral is a method that is designed to try to calculate the area underneath a curve.

For example, consider the area underneath the following curve.

Properties


The Riemann integral is known to have the following properties.

Linearity
{% {\displaystyle \int }_a^b c_1f(x)+ c_2g(x) dx = c_1{\displaystyle \int }_a^b f(x) dx + c_2{\displaystyle \int }_a^b g(x) dx %}
Additivity
{% {\displaystyle \int }_a^b f(x) dx + {\displaystyle \int }_b^c f(x) dx = {\displaystyle \int }_a^c f(x) dx %}

Riemann Lower Sum


The Riemann lower sum approximates the integral by calculating the area of the rectangles below the curve for the given mesh size.

Number of Divisions

Riemann Upper Sum


The Riemann upper sum approximates the integral by calculating the area of the rectangles above the curve for the given mesh size.

Number of Divisions

Topics


  • Formal Definition
  • Fundamental Theorem of Calculus