Math Problem Statement

Using differentiation rules, find the derivative of the function y = 5 / (4x^3 + 4).

Solution

The given function is:

y=54x3+4.y = \frac{5}{4x^3 + 4}.

We will use the quotient rule to differentiate this function. Recall that the quotient rule is given as:

ddx(f(x)g(x))=f(x)g(x)f(x)g(x)[g(x)]2,\frac{d}{dx} \left( \frac{f(x)}{g(x)} \right) = \frac{f'(x)g(x) - f(x)g'(x)}{[g(x)]^2},

where f(x)f(x) is the numerator and g(x)g(x) is the denominator.

Here:

  • f(x)=5f(x) = 5 (a constant, so f(x)=0f'(x) = 0),
  • g(x)=4x3+4g(x) = 4x^3 + 4 (its derivative is g(x)=12x2g'(x) = 12x^2).

Derivative Calculation:

Substitute into the quotient rule:

dydx=f(x)g(x)f(x)g(x)[g(x)]2.\frac{dy}{dx} = \frac{f'(x)g(x) - f(x)g'(x)}{[g(x)]^2}.

  1. Compute f(x)g(x)f'(x)g(x): Since f(x)=0f'(x) = 0, this term becomes 0(4x3+4)=00 \cdot (4x^3 + 4) = 0.
  2. Compute f(x)g(x)f(x)g'(x): 512x2=60x25 \cdot 12x^2 = 60x^2.
  3. Substitute into the formula:

dydx=060x2(4x3+4)2.\frac{dy}{dx} = \frac{0 - 60x^2}{(4x^3 + 4)^2}.

This simplifies to:

dydx=60x2(4x3+4)2.\frac{dy}{dx} = \frac{-60x^2}{(4x^3 + 4)^2}.

Final Answer:

dydx=60x2(4x3+4)2.\boxed{\frac{dy}{dx} = \frac{-60x^2}{(4x^3 + 4)^2}}.

Let me know if you would like a deeper explanation of any step or further practice problems! 😊


Related Questions:

  1. How do you apply the quotient rule to other functions with constants in the numerator?
  2. What is the derivative of y=14x3+4y = \frac{1}{4x^3 + 4}?
  3. How can we rewrite yy as a product and apply the product rule instead?
  4. What happens to the derivative if f(x)f(x) or g(x)g(x) becomes zero at a point?
  5. Can we simplify this expression further by factoring the denominator?

Tip:

Always simplify the numerator and denominator separately before substituting into the quotient rule to avoid mistakes!

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Calculus
Differentiation
Quotient Rule

Formulas

Quotient Rule: d/dx(f(x)/g(x)) = (f'(x)g(x) - f(x)g'(x)) / [g(x)]^2

Theorems

Quotient Rule of Differentiation

Suitable Grade Level

Grades 11-12