# Algebra and Trigonometry in FE Electrical and Computer

Are you an Electrical and Computer Engineering student trying to wrap your head around the concepts of algebra and trigonometry? Or maybe you’ve always been curious about these two fascinating branches of mathematics and how they apply to engineering.

Either way, you’re in the right place! In this blog, we’ll explore the fundamental principles of algebra and trigonometry and how they play a crucial role in Electrical and Computer Engineering.

We’ll dive deep into the concepts of equations, functions, and angles and see how they help solve real-world engineering and computer problems.

But this isn’t going to be your typical boring math class. We will use plenty of examples and analogies to make these concepts come to life. So buckle up and get ready to unlock the power of algebra and trigonometry in the exciting world of Electrical and Computer Engineering!

## Algebraic Concepts in Exam

Below are the five algebraic concepts in the exam:

- Real numbers and their properties
- Linear equations and functions
- Quadratic equations and functions
- Exponential and logarithmic functions
- Matrices and determinants

### 1. Real numbers and their properties

Imagine a world where numbers don’t exist. A world where we can’t quantify, measure, or count anything. It’s hard to fathom, right? Numbers are essential to our daily lives. We use them to keep track of time, money, distance, and so much more. But not all numbers are created equal. Some are real, and some are imaginary.

We’re all familiar with real numbers, and we use them daily. They’re called “real” because they represent quantities that exist in the real world. For example, if you have two apples, that’s a real quantity that can be represented by the number 2. Real numbers include integers, fractions, decimals, and irrational numbers like pi and the square root of 2.

On the other hand, imaginary numbers are a bit more abstract. The square root of negative numbers represents them, and they don’t represent real-world quantities. Instead, they’re used in complex numbers and higher-level mathematics.

Now, let’s look closely at some of the common properties of real numbers.

Property | Example |

Closure | If you add two real numbers, the result is also a real number. 2 + 3 = 5 |

Commutativity | The order in which you add or multiply real numbers doesn’t matter. 2 + 3 = 3 + 2 |

Associativity | The grouping of real numbers when adding or multiplying doesn’t matter. (2 + 3) + 4 = 2 + (3 + 4) |

Identity | There are two identity elements for addition and multiplication: 0 and 1. 2 + 0 = 2, 2 x 1 = 2. Hence, 1 is called the additive identity, and 0 is called the multiplicative identity. |

Inverse | Every real number has an additive inverse (opposite) and a multiplicative inverse (reciprocal). -2 + 2 = 0, 2 x ½ = 1. Hence -2 is the additive inverse or 2, and ½ is the multiplicative inverse of 2. |

Distributivity | Multiplication distributes over addition. 2 x (3 + 4) = (2 x 3) + (2 x 4) |

### 2. Linear equations and functions

Linear equations and functions are fundamental mathematical concepts that have countless applications in various fields, including science, engineering economics, and more.

At their core, linear equations and functions are called “linear” because they express a straight line on a graph. This is because the equation of a line can be expressed in the form y = mx + b, where m is the slope of the line, b is the y-intercept, and x and y are the variables. This equation is also known as the “slope-intercept form” of a linear equation.

Linear equations can have one, two, or three variables, depending on the dimension of the space in which they’re being used. Let’s take a closer look at each of these dimensions.

#### One-variable linear equations

These are the most basic linear equations expressed in ax + b = 0, where x is the variable, a is the coefficient, and b is a constant. The solution to this equation is a single number representing the value of x that satisfies the equation. For example, 2x + 3 = 7 is a one-variable linear equation with a solution of x = 2.

#### Two-variable linear equations

These equations are expressed in ax + by = c, where x and y are the variables, a and b are the coefficients, and c is a constant. When graphed on a two-dimensional plane, these equations represent a straight line. For example, 2x + 3y = 6 is a two-variable linear equation representing a line with a slope of -2/3 and a y-intercept of 2.

The solution to these equations is a pair of numbers (x, y) that satisfy the equation. We need 2 equations to find the solution of the straight line having 2 variables that represent the point of intersection of 2 lines represented by these equations. You can solve these equations either by substitution, comparison, or elimination.

Let’s consider the following two linear equations having 2 variables, x and y.

**Equation 1 **

y = 2x – 1

**Equation 2**

3x – y = 3

Let’s solve these equations using substitution and elimination to find their point of intersection.

##### Substitution Method

Step 1 – Solve one of the equations for one of the variables. Let’s solve Equation 1 for y – y = 2x – 1.

Step 2 – Substitute the expression for y into the other equation. Let’s substitute y = 2x – 1 into Equation 2.

3x – (2x – 1) = 3

Step 3 – Simplify and solve for x.

3x – 2x + 1 = 3

x = 2

Step 4 – Substitute the value of x into one of the equations to find the value of y. Let’s substitute x = 2 into Equation 1.

y = 2(2) – 1 = 3

Therefore, the solution of the system of equations is (2,3).

##### Comparison Method

Step 1 – Write both equations in slope-intercept form (y = mx + b).

Equation 1 – y = 2x – 1

Equation 2 – y = 3x – 3

Step 2 – Set the two equations equal to each other.

2x – 1 = 3x – 3

Step 3 – Solve for x.

x = 2

Step 4 – Substitute the value of x into one of the equations to find the value of y. Let’s substitute x = 2 into Equation 1.

y = 2(2) – 1 = 3

Therefore, the solution of the system of equations is (2,3).

#### Three-variable linear equations

These equations are expressed in ax + by + cz = d, where x, y, and z are the variables, and a, b, c, and d are the coefficients. When graphed on a three-dimensional plane, these equations represent a plane. For example, 2x + 3y – z = 6 is a three-variable linear equation representing a plane with an average vector of (2, 3, -1).

The solution to these equations is a triple of numbers (x, y, z) that satisfy the equation. We need 3 equations to find the solution of the straight line having 3 variables representing the point of intersection of 3 lines represented by these equations.

You can also solve these equations by substitution, comparison, or elimination. But these simple algebraic methods are more complex, so the solutions to such equations are usually found using matrices or cramers rule.

### 3. Quadratic equations and functions

A quadratic equation is a polynomial equation of the second degree, meaning it has one variable raised to the power of two and can be written in the general form of –

ax^{^}2 + bx + c = 0

Where a, b, and c are constants, and x is the variable.

Let’s consider the simple quadratic equation.

x^{^}2 + 2x – 3 = 0

We can use three methods to solve this equation – factorization, completing the square, and the quadratic formula.

**Method 1 – Factorization**

Step 1 – Rewrite the equation as (x + p)(x + q) = 0, where p and q are constants.

x^{^}2 + 2x – 3 = 0

(x + 3)(x – 1) = 0

Step 2 – Set each factor equal to zero and solve for x.

x + 3 = 0 or x – 1 = 0

x = -3 or x = 1

Therefore, the solutions to the quadratic equation are x = -3 and x = 1.

**Method 2 – Completing the Square**

Step 1 – Rewrite the equation as (x + a)^{^}2 + b = 0.

x^{^}2 + 2x – 3 = 0

(x^2 + 2x + 1) – 4 = 0

(x + 1)^{^}2 = 4

Step 2 – Take the square root of both sides and solve for x.

x + 1 = ±2

x = -1 ± 2

x = -3 or x = 1

Therefore, the solutions to the quadratic equation are x = -3 and x = 1.

**Method 3 – Quadratic Formula**

Step 1 – Identify the values of a, b, and c in the quadratic equation.

a = 1, b = 2, c = -3

Step 2 – Substitute these values into the quadratic formula –

x = (-b ± sqrt(b^{^}2 – 4ac)) / 2a

x = (-2 ± sqrt(2^{^}2 – 4(1)(-3))) / 2(1)

x = (-2 ± sqrt(16)) / 2

x = (-2 ± 4) / 2

Step 3 – Simplify and solve for x.

x = (-2 + 4) / 2 or x = (-2 – 4) / 2

x = 1 or x = -3

Therefore, the solutions to the quadratic equation are x = -3 and x = 1.

All three methods give the same solutions – x = -3 and x = 1.

### 4. Exponential and logarithmic functions

Exponential functions involve a constant base raised to the power of a variable, such as f(x) = a^{^}x, where a is the base and x is the variable.

Logarithmic functions, on the other hand, represent the inverse of exponential functions, such as f(x) = log_a(x), where a is the base and x is the logarithm value.

There are two main types of logarithmic functions –

**Common Logarithmic Function**– This is a logarithmic function with a base of 10, commonly denoted as f(x) = log(x).**Natural Logarithmic Function**– This is a logarithmic function with a base of the constant e (approximately 2.71828), commonly denoted as f(x) = ln(x).

Exponential and natural logarithmic functions are closely related, as they are inverse functions of each other. In other words, if f(x) = e^{^}x, then the inverse function f^{^}-1(x) = ln(x), and vice versa.

Here is a table that summarizes the shared values and relations between exponential functions and natural logarithmic functions.

Exponential Function | Natural Logarithmic Function |

f(x) = e^{^}x | f(x) = ln(x) |

f(0) = 1 | f(1) = 0 |

f(1) = e | f(e) = 1 |

f(-x) = 1/f(x) | f(1/x) = -ln(x) |

f(x+y) = f(x) * f(y) | f(xy) = f(x) + f(y) |

### 5. Matrices and determinants

Matrices are rectangular arrays of numbers or variables that are often used to represent sets of linear equations or transformations. Matrices are defined by their dimensions, given by the matrix’s number of rows and columns. For example, a 3×2 matrix has 3 rows and 2 columns.

Matrices can represent scalars and vectors in several ways. For example, a scalar can be represented as a 1×1 matrix, and a vector can be represented as an nx1 or 1xn matrix, depending on whether it is a row or column vector.

The determinant of a vector is not defined, as vectors do not have a unique determinant. Determinants are only defined for square matrices with the same number of rows and columns.

The determinant of a 2×2 matrix with elements the formula gives a, b, c, and d.

| a b |

| c d | = ad – bc

The determinant can be found for larger matrices using more complex methods, such as row reduction or cofactor expansion.

If the matrix has determinant zero, it’s called a singular matrix. But we can tell if the matrix is singular without finding its determinant if it’s fulfilling the following conditions or properties.

Property | Explanation |

Zero Row/Column | If any row or column of a matrix is all 0’s, then the determinant of the matrix is 0, and thus it is singular. |

Linear Dependence | If the columns of a matrix are linearly dependent, then the determinant of the matrix is 0, and thus it is singular. |

Rank Deficiency | If the rank of a matrix is less than its order (i.e., the number of rows or columns), then the determinant of the matrix is 0, and thus it is singular. |

Singular Factors | If a matrix can be factored into the product of two matrices, one of which is singular, then the original matrix is also singular. |

## Trigonometric Concepts in Exam

Below are the four trigonometric concepts in the exam:

- Trigonometric functions and their properties
- Trigonometric identities and equations
- Inverse trigonometric functions
- Trigonometric applications in engineering problems

### 1. Trigonometric functions and their properties

Trigonometric functions are widely used in mathematics, science, engineering, and many other fields. They describe the relationship between the angles and sides of a right triangle and have many important applications in fields like navigation, physics, and signal processing.

The two main trigonometric functions are sine (sin) and cosine (cos), defined as the ratios of the length of the opposite side and adjacent side to an acute angle in a right triangle, respectively. The tangent (tan) function is the ratio of the opposite side to the adjacent side.

The reciprocals of these functions are cosecant (csc), secant (sec), and cotangent (cot), which are defined as the inverses of the sine, cosine, and tangent functions, respectively.

The standard values of all six trigonometric functions for 0, 30, 45, 60, and 90 degrees are:

Angle (deg) | sin | cos | tan | csc | sec | cot |

0 | 0 | 1 | 0 | NaN | 1 | NaN |

30 | 1/2 | √3/2 | √3/3 | 2 | 2/√3 | √3/3 |

45 | √2/2 | √2/2 | 1 | √2 | √2 | 1 |

60 | √3/2 | 1/2 | √3 | 2/√3 | 2 | 1/√3 |

90 | 1 | 0 | ∞ | 1 | ∞ | 0 |

### 2. Trigonometric identities and equations

Trigonometric identities are equations that relate different trigonometric functions of the same or different angles. They are used to simplify trigonometric expressions and equations, to prove other mathematical results, and to solve trigonometric problems.

Here are some common trigonometric identities:

#### Pythagorean identities

Based on the Pythagorean theorem, these equations relate an angle’s sine, cosine, and tangent functions. The most common Pythagorean identities are –

sin²θ + cos²θ = 1

1 + tan²θ = sec²θ

1 + cot²θ = csc²θ

#### Even-odd identities

These equations relate the values of trigonometric functions for positive and negative angles. The most common even-odd identities are:

sin(-θ) = -sinθ

cos(-θ) = cosθ

tan(-θ) = -tanθ

#### Sum and difference identities

These equations relate the trigonometric functions of the sum and difference of two angles to the trigonometric functions of the individual angles. The most common sum and difference identities are:

sin(α + β) = sinαcosβ + cosαsinβ

cos(α + β) = cosαcosβ – sinαsinβ

tan(α + β) = (tanα + tanβ) / (1 – tanαtanβ)

#### Dual angle identities

These equations relate a double angle’s trigonometric functions to the original angle’s trigonometric functions. The most common dual-angle identities are:

sin2θ = 2sinθcosθ

cos2θ = cos²θ – sin²θ

tan2θ = (2tanθ) / (1 – tan²θ)

Trigonometric identities are used in various mathematical contexts, including calculus, differential equations, and geometry. They are instrumental in solving trigonometric equations and in proving other mathematical results. They also have applications in physics, engineering, and other fields involving periodic function analysis.

### 3. Inverse trigonometric functions

Inverse trigonometric functions find the angle that gives a certain trigonometric ratio.

Let’s take the example of finding the angle whose cosine is 0. We already know from the table in the previous section that the cosine of 90 degrees is 0, but what if you need to find the angle that gives us a cosine of 0 or whatever else. To do this, we use the inverse cosine function (arccosine). Mathematically, we can write it as.

cos⁻¹(0) = 90°

This means that the angle whose cosine is 0 is 90 degrees. Similarly, we can use inverse sine and inverse tangent functions to find angles that give certain sine and tangent ratios. For example –

sin⁻¹(1) = 90°

tan⁻¹(∞) = 90°

### 4. Trigonometric applications in engineering problems

Below are some examples of trigonometric applications in various engineering fields:

**General computer science**– Trigonometry is used in computer graphics to render 3D objects, animations, and special effects. Trigonometric functions are also used in digital signal processing and image processing.**Machine learning**– Trigonometric functions are used in machine learning algorithms to calculate the similarity between vectors, an essential step in clustering and classification.**Aviation**– Trigonometry is used for navigation, calculating distances and angles, and determining aircraft performance parameters such as lift and drag.**Radar**– Trigonometry calculates the position and velocity of moving objects and the direction and range of radio waves.**Electronics**– Electronic engineers use trigonometric functions to describe AC circuits’ behavior, including the phase and amplitude of signals.**Signal processing**– Trigonometry is used extensively in signal processing to analyze and manipulate signals, including filtering, demodulation, and modulation

## Resources for Preparing for Algebra and Trigonometry on the FE Exam

Preparing for the Algebra and Trigonometry section of the FE Exam can be challenging, but don’t worry – plenty of resources are available to help you succeed! One excellent option is Study for FE, your online study and counseling portal offering comprehensive study materials and practice exams tailored to the FE Exam.

To make the most of your study time, here are some tips and tricks to keep in mind –

**Start with the basics **– Review fundamental concepts and formulas to build a strong foundation for more complex problems.

**Use practice problems **– Work through as many problems as possible to get comfortable with the format and types of questions you’ll see on the exam.

**Understand the underlying concepts **– Don’t just memorize equations and formulas – make sure you understand the concepts behind them so you can apply them to new situations.

**Break it down **– Break down complex problems into smaller, more manageable parts to make them easier to solve.

**Focus on your weaknesses **– Acknowledge critical areas and topics where you need more practice and spend extra time on those topics.

**Stay organized **– Keep track of your progress and study materials to avoid wasting time searching for information.

By following these tips and using resources like Study for FE, you can feel confident and prepared for the Algebra and Trigonometry section of the FE Exam. Click here to learn more about **“Study for FE”** and start your journey toward exam success!

### Conclusion

Understanding algebra and trigonometry is crucial for success in the FE electrical and computer exam and the engineering profession. These concepts are the building blocks of more advanced topics, and a strong foundation is essential for tackling complex engineering problems.

Furthermore, algebra and trigonometry are used extensively in various engineering applications, from circuit design to signal processing. Engineers can confidently navigate the field’s challenges and contribute to society by mastering these fundamental concepts.

So, whether you’re preparing for the FE exam or pursuing a career in electrical engineering, don’t underestimate the importance of algebra and trigonometry – they are the keys to success!