What is integration?

Introduction Look at the following graph of the function $$ f(x) = \sqrt{4-x^2}, \quad -2 < x < 2$$ and the region highlighted in orange. Can you compute its area? As you may have noticed, the highlighted area is one quarter of a circle. Since the area of a full circle is \(\pi r^2\) where \(r\) is the circle’s radius […]