General Mathematics JAMB

Differentiation

Overview

Welcome to the course material on Differentiation in Calculus. In this topic, we delve into the fundamental concept of finding the rate at which a function changes. This process, known as differentiation, is crucial in various real-world applications such as physics, engineering, economics, and many other fields.

One of the primary objectives of this topic is to understand the concept of finding the derivative of a function. The derivative gives us information about how the function is changing at any given point. It helps us determine the slope of the tangent line to the curve at a specific point and provides insights into the behavior of the function.

When differentiating, we are essentially finding the rate of change of the function with respect to its input variable. This rate of change can give us vital information about the behavior of the function, whether it is increasing, decreasing, or remaining constant at a certain point.

Moreover, the process of differentiation allows us to identify critical points such as local maxima and minima of a function. These points are significant in optimizing functions and solving real-world problems where we aim to maximize or minimize certain quantities.

As we progress through this course material, we will also explore different techniques for differentiating various types of functions, including explicit algebraic functions and simple trigonometric functions like sine, cosine, and tangent. Understanding the differentiation rules for these functions is essential in solving more complex problems and applying calculus in diverse scenarios.

By the end of this course material, you will be adept at finding derivatives, understanding their significance, and applying differentiation to solve a wide range of mathematical problems. Let's embark on this journey of exploring the fascinating world of calculus and differentiation!

Objectives

  1. Understand the concept of differentiation
  2. Apply differentiation rules to simple trigonometric functions
  3. Apply differentiation rules to algebraic functions
  4. Apply differentiation to optimize functions
  5. Solve problems involving rates of change using differentiation
  6. Understand the geometric interpretation of differentiation

Lesson Note

Differentiation can be understood as the process of finding the *derivative* of a function. The derivative of a function at a particular point provides the slope of the tangent line to the function's graph at that point. Imagine a graph of a curve:

Lesson Evaluation

Congratulations on completing the lesson on Differentiation. Now that youve explored the key concepts and ideas, its time to put your knowledge to the test. This section offers a variety of practice questions designed to reinforce your understanding and help you gauge your grasp of the material.

You will encounter a mix of question types, including multiple-choice questions, short answer questions, and essay questions. Each question is thoughtfully crafted to assess different aspects of your knowledge and critical thinking skills.

Use this evaluation section as an opportunity to reinforce your understanding of the topic and to identify any areas where you may need additional study. Don't be discouraged by any challenges you encounter; instead, view them as opportunities for growth and improvement.

  1. Find the derivative of the function f(x) = 3x^2 + 4x - 2. A. f'(x) = 6x + 4 B. f'(x) = 3x^2 + 2x C. f'(x) = 6x + 2 D. f'(x) = 3x^2 + 4 Answer: A. f'(x) = 6x + 4
  2. Compute the derivative of g(x) = 5x^4 - 6x^3 + 2x^2. A. g'(x) = 20x^3 - 18x^2 + 4x B. g'(x) = 25x^3 - 18x^2 + 4x C. g'(x) = 20x^4 - 18x^3 + 4x D. g'(x) = 20x^4 - 18x^3 + 2x Answer: A. g'(x) = 20x^3 - 18x^2 + 4x
  3. Find the derivative of h(x) = sin(x) + cos(x). A. h'(x) = cos(x) - sin(x) B. h'(x) = sin(x) + sin(x) C. h'(x) = cos(x) + cos(x) D. h'(x) = sin(x) - cos(x) Answer: A. h'(x) = cos(x) - sin(x)
  4. Calculate the derivative of k(x) = 2x^3 - 5x^2 + 3x - 7. A. k'(x) = 6x^2 - 10x + 3 B. k'(x) = 6x^2 - 10x + 7 C. k'(x) = 6x^2 - 5x + 3 D. k'(x) = 6x^2 - 5x + 7 Answer: C. k'(x) = 6x^2 - 5x + 3
  5. Determine the derivative of m(x) = e^x + x^2. A. m'(x) = e^x + 2x B. m'(x) = e^x + 2 C. m'(x) = e^x - x^2 D. m'(x) = e^x Answer: A. m'(x) = e^x + 2x
  6. Find the derivative of n(x) = ln(x) + x. A. n'(x) = 1/x + 1 B. n'(x) = 1/x - 1 C. n'(x) = x - 1 D. n'(x) = x + 1 Answer: A. n'(x) = 1/x + 1
  7. Calculate the derivative of p(x) = 4x^5 - 2x^3 + x^2 - 3. A. p'(x) = 20x^4 - 6x^2 + 2x B. p'(x) = 20x^4 - 6x^2 C. p'(x) = 20x^5 - 6x^3 + 2x D. p'(x) = 20x^5 - 6x^3 Answer: B. p'(x) = 20x^4 - 6x^2
  8. Find the derivative of q(x) = 2sin(x) + 3cos(x). A. q'(x) = 2cos(x) - 3sin(x) B. q'(x) = 2sin(x) - 3cos(x) C. q'(x) = 2cos(x) + 3sin(x) D. q'(x) = 2sin(x) + 3cos(x) Answer: A. q'(x) = 2cos(x) - 3sin(x)
  9. Compute the derivative of r(x) = tan(x) + x^2. A. r'(x) = sec^2(x) + 2x B. r'(x) = sec^2(x) - 2x C. r'(x) = sec(x) + 2x D. r'(x) = sec(x) - 2x Answer: A. r'(x) = sec^2(x) + 2x

Revision Questions

Wondering what past questions for this topic looks like? Here are a number of questions about Differentiation from previous years

Question 1 Report

The roots of a quadratic equation in x, are -m and 2n. Fine equation.

Question 1 Report

Find the derivatives of y = sin 4x

Answer Details

To find the derivative of \( y = \sin 4x \), you need to use the chain rule. The chain rule helps you take the derivative of a function inside another function.


First, recall that the derivative of \( \sin u \) with respect to \( u \) is \( \cos u \):

\[ \frac{d}{du} (\sin u) = \cos u \]


In this problem, \( u = 4x \). So when you differentiate \( \sin 4x \) with respect to \( x \), apply the chain rule:


  • Differentiate the outer function (\( \sin \)) first: \[ \frac{d}{dx} (\sin 4x) = \cos(4x) \cdot \frac{d}{dx}(4x) \]
  • Now take the derivative of the inside function, \( 4x \), with respect to \( x \), which is \( 4 \).

Putting it all together, you have:

\[ \frac{d}{dx} (\sin 4x) = \cos(4x) \cdot 4 = 4\cos(4x) \]


This means the derivative is 4cos4x. The result is positive, not negative, and the function is cosine (not sine) because the derivative of sine is cosine.


Question 1 Report


In the diagram, \(\overline{AD}\) is a diameter of a circle with Centre O. If ABD is a triangle in a semi-circle ∠OAB=34",

find: (a) ∠OAB (b) ∠OCB

 

Answer Details

In the diagram, \(\overline{AD}\) is a diameter of the circle with centre \(O\), \(B\) lies on the circle, and \(BC\) is a tangent to the circle at \(B\). It is given that \(\angle OAB = 34^\circ\).

(a) \(\angle OAB\)

\(OA\) and \(OB\) are radii, so triangle \(OAB\) is isosceles and \(\angle OBA = \angle OAB\):

\[ \angle OAB = 34^\circ \]

(b) \(\angle OCB\)

Since \(AD\) is a diameter, the angle in the semicircle is a right angle:

\[ \angle ABD = 90^\circ \]

The angle subtended at the centre is twice the angle at the circumference on the same arc \(BD\), so

\[ \angle BOC = \angle BOD = 2 \times \angle OAB = 2 \times 34^\circ = 68^\circ \]

A tangent is perpendicular to the radius at the point of contact, so at \(B\):

\[ \angle OBC = 90^\circ \]

In triangle \(OBC\), the angles sum to \(180^\circ\):

\[ \angle BOC + \angle OBC + \angle OCB = 180^\circ \] \[ 68^\circ + 90^\circ + \angle OCB = 180^\circ \] \[ \angle OCB = 180^\circ - 158^\circ = 22^\circ \]