Derivative of 5*x^3-9*x+4

1. Differentiate $\left(5 x^{3} - 9 x\right) + 4$ term by term:

   1. Differentiate $5 x^{3} - 9 x$ term by term:

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

         1. Apply the power rule: $x^{3}$ goes to $3 x^{2}$

         So, the result is: $15 x^{2}$

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

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

         So, the result is: $-9$

      The result is: $15 x^{2} - 9$

   2. The derivative of the constant $4$ is zero.

   The result is: $15 x^{2} - 9$

The answer is: