Video Lessons

Mathematics

Elroi Academy Video Lessons are all on YouTube available, but for your convenience, we are making some of them available here on our website in convenient Channels. We are doing it systematically, so come back to see more as they are added.

Financial

29 Videos

Introduction to Financial Mathematics

6:37

Deriving the formula for simple growth

3:41

Sum to infinity word problem

5:38

Example of Simple and Compound interest

6:59

Solving a past or present value

9:25

Solving the interest rate

8:58

Solving the the number of times interest is earned or time period over which interest was earned

11:55

Introduction to Depreciation

6:08

Depreciation examples

8:04

Different periods of Compound Interest

7:53

Comparing different compounding periods

9:25

Nominal and effective interest rates

7:11

Using the effective interest rates

9:03

Formulas for changes during investment period

11:42

Investment changes formulas example

8:30

Deriving the formula for the Future value of an Annuity

13:10

Future value of an annuity example

5:55

The Basics of Sinking Funds

5:32

Sinking Fund Example

12:49

Time Value of Money

3:39

Time Value of Money Example 1

3:09

Time Value of Money Example 2

6:52

Present Value of an annuity: Deriving the formula

6:19

Present Value of an annuity example1

5:36

Present Value of an annuity Loan Repayments

5:01

Present Value of an annuity Loan Repayments example 1

5:25

Present Value of an annuity Loan Repayments example 2

7:10

Outstanding Balance on loan

3:32

Outstanding Balance on loan example

8:38

Introduction to Number Patterns

6 Videos

Introduction to number patterns

9:57

Number Patterns

7:44

Arithmetic Sequence

7:50

Arithmetic Sequence more challenging examples

13:31

Arithmetic Sequence Example

4:31

Arithmetic Sequence Example

6:24

Series

19 Videos

Arithmetic Series

Sigma Notation

6:16

Sigma Notation Laws

12:16

Sigma Notation Example

3:47

Introduction to series

5:18

Arithmetic Series Example

4:22

Arithmetic series and sigma notation Example

4:48

Arithmetic series and sigma notation

9:16

Basics of the Arithmetic Series

7:45

Arithmetic series Word Problem

9:14

Geometric and Infinite Series

Basics of the Geometric series

8:12

Geometric series and sigma notation

6:20

Geometric series example

4:19

Geometric series example

4:54

Introduction to number patterns

9:57

Basics of Sum to infinity

7:03

Introduction to number patterns

9:57

Sum to infinity example

3:31

Sum to infinity example

1:57

Sum to infinity word problem

5:38

Analytical Geometry

13 Videos

Introduction to Analytic Geometry

Analytical Geometry: the midpoint formula

6:01

Analytical Geometry: The distance formula

7:21

Analytical Geometry: Gradient Formula

10:38

Analytical Geometry: Parallelograms

12:52

Analytical Geometry: other quadrilaterals

10:20

Analytical Geometry: Angle of inclination

11:18

Circle Geometry

Analytical Geometry: Introduction to circles

7:15

Analytical Geometry: Completing the square to find the equation of a circle

7:15

Analytical Geomety: Circle Examples

8:45

Analytical Geometry: More Circle Examples

9:14

Introduction to Trigonometry

13:11

Analytical Gemoetry: Tangents to Circles

5:58

Analytical Geometry: Tangent to Circles Example 1

4:19

Trigonometry

108 Videos

Introduction to Trigonometry

Introduction to Trigonometry

13:11

Theorem of Pythagoras

9:42

Solving Right-triangles Example 1

6:49

Solving right angle triangles example 2

4:51

Solving trigonometric eqautions Example 1

2:59

Solving trigonometric equations Example 2

4:09

Solving trigonometric eqautions Example 3

3:17

The inverse trigonometric ratios

11:58

Inverse trig ratios example 1

6:39

The CAST diagram

14:35

Representing angles on the Cartesian plane

14:08

Representing Angles on the cartesian plane Example 1

3:44

Representing Angles on the cartesian plane Example 2

3:35

Representing Angles on the cartesian plane Example 3

8:36

Special Angles

13:06

Special Angles Examples

5:01

Reduction Formulas

Reduction Formulas

15:21

Reduction Formulas Example 1

3:03

Reduction Formulas Example 2

1:47

Reduction Formulas Example 3

10:20

Reduction Formulas Example 4

10:20

Reduction Formulas Example 5

10:20

Negative Angles

3:58

Negative Angles Example 1

2:56

Negative Angles Example 2

2:06

Negative Angles Example 3

2:06

Negative Angles Example 4

1:18

Negative Angles Example 5

6:18

Co-ratios

5:00

Co-ratios in the cartesian plane

10:19

Co-ratios Example 1

2:50

Co-ratios Example 2

2:14

Co-ratios Example 3

5:55

Co-ratios Example 4

3:08

Co-ratios Example 5

5:50

Identities

Fundamental Trigonometric Identities

12:01

Fundamental trig identities example 2

8:44

Fundamental trig identities example 3

5:01

Fundamental trig identities example 4

5:01

Fundamental trig identities example 5

5:53

Fundamental trig identities example 6

5:01

Fundamental trig identities example 7

5:01

Double Angle Identities

6:11

Double Angle Example 1

4:58

Double Angle Example 2

8:18

Double Angle Example 3

4:44

Double Angle Example 4

3:14

Double Angle Example 5

3:33

Double Angle Example 6

7:04

Double Angle Example 7

7:26

Compound Angle Identities

14:53

Compound Identities Example 1

14:30

Compound Identities Example 2

1:36

Equations

Solving Trigonometric Equations

14:59

Solving Trigonometric Equations summary

5:01

Trigonometric Equations example 1

3:38

Trigonometric Equations example 2

3:36

Trigonometric Equations example 3

5:01

Trigonometric Equations example 4

2:41

Trigonometric Equations example 5

3:46

Trigonometric Equations example 6

5:01

Trigonometric Equations example 7

4:40

Trigonometric Equations example 8

4:04

Trigonometric Equations example 9

5:00

Trigonometric Equations example 10

4:14

Trigonometric Equations example 11

5:54

Trigonometric Equations example 12

5:00

Trigonometric Equations example 13

4:21

Trigonometric Equations example 14

5:44

Trigonometric Equations example 15

6:10

Trigonometric Equations example 16

7:24

Trigonometric Equations example 17

7:07

More complex Trigonometric EquationsQuadratic Equations

10:28

More Complex Trigonometric Equations example 1

2:46

More Complex Trigonometric Equations example 2

8:10

More Complex Trigonometric Equations example 3

5:58

More Complex Trigonometric Equations example 4

10:26

More Complex Trigonometric Equations example 5

7:51

More Complex Trigonometric Equations example 6

10:12

More Complex Trigonometric Equations example 7

8:22

More Complex Trigonometric Equations example 8

8:23

Graphs

Basic Form for Sine graph

25:30

General Form for Sine graph, amplitude and center line

18:28

General Form for Sine graph, period

19:27

Sine graph Example 1

8:55

Sine graph Example 2

6:39

Sine graph Example 3

7:27

General Form for Sine graph, horizontal shift

19:08

Basic Form for cosine graph

14:12

Cosine Graph Example 1

7:28

Cosine Graph Example 2

5:43

Cosine Graph Example 3

4:20

Cosine Graph Example 4

5:17

Cosine Graph Example 5

5:51

Cosine Graph Example 6

4:45

Cosine Graph Example 7

3:45

Cosine Graph Example 8

4:29

Cosine Graph Example 9

4:17

Application

2&3D Trigonometric Applications Introduction

11:07

2&3D Trigonometric Applications Sine Rule

15:11

2&3D Trigonometric Applications Cosine Rule

17:45

2&3D Trigonometric Applications Summary

9:00

2&3D Trigonometric Applications Example 1a

10:14

2&3D Trigonometric Applications Example 1b

8:27

2&3D Trigonometric Applications Example 1c

14:56

2&3D Trigonometric Applications Example 2

16:52

2&3D Trigonometric Applications Example 3

15:47

2&3D Trigonometric Applications Example 4

19:19

Functions And Graphs

79 Videos

Introductory

Functions and Graphs Definition

18:30

The domain of a function

20:05

Range of a function

21:17

Graphs intro

15:28

Linear Function

The linear function and its graph

12:11

Function finding the equation of a straight line

11:39

Functions and Graphs of the Quadratic Function

19:51

Drawing a linear function

8:32

Finding the equation of a linear function from a parallel line

9:57

Finding the equation of a linear function given gradient and/or -y-intercept

2:06

Finding the equation of a linear function from two points

3:19

Finding the equation of a linear function from a perpendicular line

3:38

Quadratic Function

Functions and Graphs of the Quadratic Function

19:51

Converting between formats f(x)=a(x-p)^2+q and f(x)=ax^2+bx+c

10:27

Function finding the equation of the quadratic function

10:19

Range of quadratic functions

6:25

Domain of an even root function

4:12

Converting from ax^2+bx+c to a(x-p)^2+q

2:38

Completing the square

1:52

Exam type question: parabola

4:59

Converting Hint video

2:03

Exam type question: Parabola and straight line I Question 1

4:39

Exam type question: Parabola and straight line I Question 2

0:50

Exam type question: Parabola and straight line I Question 3

6:48

Exam type question parabola and straight line I Question 4

4:56

Drawing Parabola Theory

3:27

Drawing Parabola Example

4:01

Drawing Parabola Example 02

3:12

Drawing Parabola Example 03

2:24

Finding the equation of a quadratic function given the turning point

1:45

Example of finding the equation of a quadratic function given the turning point

2:01

Finding the equation of a quadratic function given the roots

3:16

Example of Finding the equation of a quadratic function given the roots

2:26

Exponential Functions

Range of Exponential functions

6:43

The Exponential Function

8:57

Examples of drawing exponential functions

7:10

Exam type question Parabola and Exponential function I

4:50

Exam type question of Parabola and Exponential function II

2:18

Exam type question of Parabola and Exponential function III

2:04

Exam type question of Parabola and Exponential functions IV

2:00

Exam type question of Parabola and Exponential functions V

1:48

HINT VIDEO Exam type question Parabola and Exponential function VI

9:04

The Hyperbolic Function

The Basic of the Hyperbola

7:30

The Hyperbola

9:44

Examples of drawing Hyperbola

9:16

Why the the Hyperbola has its shape

8:05

Range of hyperbolic functions

6:55

Domain of a rational function

8:04

Exam type question Hyperbola function I QI

3:29

Exam type question Hyperbola function I QII

5:53

Exam type question Hyperbola function I QIII

4:11

Hyperbola function Q1

1:04

Hyperbola function Q2

1:51

Hyperbola function Q3

4:05

Hyperbola function Q4

3:52

Hyperbola function Q5

4:49

Exam type question Parabola and hyperbola function Question I

2:26

Exam type question Parabola and hyperbola function Question II

3:10

Exam type question Parabola and hyperbola function III

2:28

Exam type question Parabola and hyperbola function Question IV

1:32

Exam type question Parabola and hyperbola function Question V

3:52

Transformation of Functions

Translation of a Function

6:14

Examples of Translated Parabolas and Hyperbolas

8:39

Understanding reflection of a Function

7:09

Examples of Function reflections

10:48

The Inverse of a Function

Introduction to the inverse function

12:45

The inverse of the parabola

10:07

The Inverse of the Exponential Function: Logarithms

7:19

Graph of logarithmic function

5:25

Exam type question on the exponential function and its inverse I

2:44

Exam type question on the exponential function and its inverse II

5:47

Exam type question on the exponential function and its inverse III

0:57

Exam type question on the exponential function and its inverse IV

1:17

Exam type question on the exponential function and its inverse V

1:29

Exam type question on the exponential function and its inverse VI

4:26

Sumarries and classroom discussions

Revision functions and graphs

1:16:06

Algebra of graphs

16:23

Mathematics | Prelim Preperation 2014 Paper 1 | Functions and Graphs | Comments on Student attempts

25:43

Question 4 Functions and Graphs Exam Revision

55:07

The Quadratic sequence

4 Videos

The Quadratic sequence

4:23

Quadratic Sequence Example

4:17

Quadratic Sequence deriving the formulas and alternative formulas

7:47

Quadratic Sequence Example using easier formulas

7:04

Euclidean Geometry: Introduction

10 Videos

Geometry Introduction and Adjacent Angles

9:50

Revolution and perpendicular line

11:53

Parallel Lines

12:17

Corresponding Angles

11:15

Alterate Angles

4:02

Interior angles of triangle

12:25

Exterior Angles of triangle

9:12

Congruent triangles

8:17

Isosceles triangle

13:24

Parallel lines are equidistant

9:56