4.7 Summary
After handling algebra in the last chapter, we tackled geometry here. The concept of ‘‘function’’ is core to most of mathematics and its application areas like physics. Functions allow us to connect one or more inputs with some kind of useful output. Plotting functions is a good way to visualize their behavior.
Two- and three-dimensional spaces are familiar to us and we learned and reviewed the common tools to allow us to effectively use them. Trigonometry demonstrates beautiful connections between algebra and geometry and falls out naturally from relationships like the Pythagorean theorem.
The complex ‘‘plane’’ is like the real plane R2 but the algebra and geometry gives more structure than points alone can provide. Euler’s formula nicely ties together complex numbers and trigonometry in an easy-to-use notation that is the basis for how we define many quantum operations in chapter 7
