Even Functions

A function is an Even Function if the following equation is true:

f(-x) = f(x)

This is true for the parabola

y=x^2

  • x=+2 –> y=+4
  • x=-2 –> y=+4
  • x=+3 –> y=+9
  • x=-3 –> y=+9

This is also true for the Cosine Function.

Appendix A

Later, in Tensors, we will want to prove something in one of the steps done in that proof is making changes to the sine functions and cosine functions based on whether they are even or odd.