# Section 12.2 Question 2

## How are other higher derivatives calculated?

The second derivative is an example of a higher derivative. By taking the derivative of the second derivative, we obtain another higher derivative, the third derivative. The notation for the third derivative follows the pattern established by the second derivative.

By taking the derivative of another derivative, we may calculate other higher derivatives. These higher derivatives may be written in a similar manner. For derivatives higher than the third derivative, we write the nth derivative as f (n)(x).

For the function (x) = 5x4 – 7x2 + 2x – 1, the first and second derivatives were calculated earlier as The derivative of the second derivative, the third derivative, is calculated by taking the derivative of the second derivative. We can continue to take the derivative of the derivative to obtain higher derivatives: Since the derivative of a constant is zero, the fifth derivative and those higher are equal to zero.

### Example 4      Calculate the Fourth Derivative

Let Find the fourth derivative h(4) (x).

Solution The first derivative is We can follow the same strategy to get the second derivative, the third derivative, and the fourth derivative, ### Example 5     Calculate the Third Derivative

Solution To find the first derivative, use the Product Rule for Derivatives with the factors and corresponding derivatives, The second derivative is simply the derivative of the first derivative or Rewrite as -1 to make the next derivative easy to do. The third derivative is The third derivative is rewritten with a positive exponent as .