Problem

Find the Fourth Derivative f(x)=(x-2)/(x-3)

The question asks for the computation of the fourth derivative of the given function f(x) = (x - 2)/(x - 3). To find the fourth derivative means to differentiate the function with respect to x four consecutive times. The process involves applying the rules of differentiation, such as the quotient rule, possibly along with the product and chain rules, to find the first, second, third, and eventually the fourth derivative of the function.

$f \left(\right. x \left.\right) = \frac{x - 2}{x - 3}$

Answer

Expert–verified

Solution:

Step 1: Compute the first derivative

Step 1.1: Apply the Quotient Rule

The Quotient Rule is $\frac{d}{dx} \left( \frac{f(x)}{g(x)} \right) = \frac{g(x) \frac{d}{dx} f(x) - f(x) \frac{d}{dx} g(x)}{(g(x))^2}$, where $f(x) = x - 2$ and $g(x) = x - 3$.

Step 1.2: Perform differentiation

Step 1.2.1: Use the Sum Rule

The derivative of $x - 2$ is the sum of the derivatives of $x$ and $-2$.

Step 1.2.2: Apply the Power Rule

The Power Rule states $\frac{d}{dx} x^n = n x^{n-1}$, where $n = 1$.

Step 1.2.3: Differentiate the constant

The derivative of a constant is $0$.

Step 1.2.4: Simplify the derivative

Combine like terms and simplify the expression.

Step 1.3: Finalize the first derivative

Simplify the expression to get the first derivative in its simplest form.

Step 2: Compute the second derivative

Step 2.1: Apply the Product Rule

The Product Rule is $\frac{d}{dx} (f(x)g(x)) = f(x) \frac{d}{dx} g(x) + g(x) \frac{d}{dx} f(x)$, where $f(x) = -1$ and $g(x) = \frac{1}{(x - 3)^2}$.

Step 2.2: Simplify using exponent rules

Rewrite the expression using the negative exponent rule.

Step 2.3: Apply the Chain Rule

The Chain Rule is $\frac{d}{dx} f(g(x)) = f'(g(x)) g'(x)$, where $f(x) = x^{-2}$ and $g(x) = x - 3$.

Step 2.4: Differentiate and simplify

Perform differentiation and simplify the expression to find the second derivative.

Step 3: Compute the third derivative

Step 3.1: Use the Constant Multiple Rule

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

Step 3.2: Apply the Chain Rule

Use the Chain Rule with $f(x) = x^{-3}$ and $g(x) = x - 3$.

Step 3.3: Differentiate and simplify

Differentiate and simplify the expression to find the third derivative.

Step 4: Compute the fourth derivative

Step 4.1: Use the Constant Multiple Rule

Apply the Constant Multiple Rule to the third derivative.

Step 4.2: Apply the Chain Rule

Use the Chain Rule with $f(x) = x^{-4}$ and $g(x) = x - 3$.

Step 4.3: Differentiate and simplify

Differentiate and simplify the expression to find the fourth derivative.

Step 5: Final result

The fourth derivative of $f(x)$ with respect to $x$ is $\frac{24}{(x - 3)^5}$.

Knowledge Notes:

  1. Quotient Rule: Used to differentiate functions that are ratios of two differentiable functions.

  2. Sum Rule: The derivative of a sum of functions is the sum of the derivatives.

  3. Power Rule: A basic differentiation rule that gives the derivative of a power function.

  4. Product Rule: Used when differentiating a product of two functions.

  5. Chain Rule: Used to differentiate the composition of functions.

  6. Constant Multiple Rule: The derivative of a constant times a function is the constant times the derivative of the function.

  7. Negative Exponent Rule: For any nonzero number $b$ and integer $n$, $b^{-n} = \frac{1}{b^n}$.

  8. Simplification: The process of reducing a mathematical expression to its simplest form by combining like terms and applying arithmetic operations.

link_gpt