Derivative of z^2+2z-1

1. Differentiate $\left(z^{2} + 2 z\right) - 1$ term by term:

   1. Differentiate $z^{2} + 2 z$ term by term:

      1. Apply the power rule: $z^{2}$ goes to $2 z$

      2. The derivative of a constant times a function is the constant times the derivative of the function.

         1. Apply the power rule: $z$ goes to $1$

         So, the result is: $2$

      The result is: $2 z + 2$

   2. The derivative of the constant $-1$ is zero.

   The result is: $2 z + 2$

The answer is:

$$2 z + 2$$