Algebra is firstly taken from a book, written by Khwarizmi(780-850 CE), which is about calculation and equations. It is a branch of mathematics in which letters are used instead of numbers. Each letter can represent a specific number in one place, and a completely different number in another. Notations and symbols are also used in algebra to show the relationship between numbers. I remember about 17 years ago when I was an ordinary student in applied mathematics(ordinary graduate today!), I was so curious about some research in algebra, done by Maryam Mirzakhani(1977–2017), at Harvard University about analogous counting problem. This science has evolved a lot throughout history and now includes many branches.

Elementary algebra includes basic operations on four main operations. After defining the signs by which fixed numbers and variables are separated, methods are used to solve the equations. A polynomial is an expression that is the sum of a finite number of non-zero terms, each term consisting of the product of a constant and a finite number of variables raised to whole number powers.

Abstract algebra or modern algebra is a group in the algebra family that studies advanced algebraic structures such as groups, rings, and fields. Algebraic structures, with their associated homomorphisms, form mathematical categories. Category theory is a formalism that allows a unified way for expressing properties and constructions that are similar for various structures. Abstract algebra is so popular and used in many fields of mathematics and engineering sciences. For instance, algebraic topology uses algebraic objects to study topologies. The Poincaré conjecture proved in 2003, asserts that the fundamental group of a manifold, which encodes information about connectedness, can be used to determine whether a manifold is a sphere or not. Algebraic number theory studies various number rings that generalize the set of integers.

I believe that the most influencing branch of algebra in other sciences is linear algebra. Let’s suppose that you went out for jogging, that can’t be easy these days with Covid-19 lockdown, and suddenly a beautiful flower catches all your attention. Please don’t be rush and pick it, just take a picture, others can enjoy it, as well. After a while when you look at this picture, you can recognize the flower in the image, because the human brain has evolved over millions of years and able to detect such a thing. We are unaware of the operations that take place in the background of our brains and enable us to recognize the colors in the image, they are trained to do this for us automatically. But, it’s not easy to do such a thing with a machine, that’s why this is one of the most active research areas in machine learning and deep learning. Actually, the fundamental question is: “How does a machine store this image?” You probably know that today’s computers are designed to process only two numbers, 0 and 1. Now, how can an image like this with different features be stored? This is done by storing the pixel intensity in a structure called a “matrix”.

The main topics in linear algebra are vectors and matrices. Vectors are geometric objects that have length and direction. For example, we can mention speed and force, both of which are vector quantities. Each vector is represented by an arrow whose length and direction indicate the size and direction of the vector.

The addition of two or more vectors can be done based on ease of use using parallelogram methods or the method of images in which each vector is decomposed into its components along the coordinate axes. A vector space is a collection of vectors, which may be added together and multiplied by scalars. Scalars generally can be picked up from any field but normally are real numbers.

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