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These video tutorials are presented by Roderick V. James PhD. EE, Adjunct Professor at Houston Community College. Dr. James has been involved with education for the past ten years. His past teaching experience at the Keller Graduate School of Management of DeVry University included the duties of Curriculum Manager for Project Management. 

Currently, Dr. James teaches a range of math courses including Fundamentals of Mathematics I & II, College Algebra, Trigonometry, Pre-Calculus, Calculus, Statistics and Finite Mathematics.

The Business of X

In the study of mathematics, once you get past arithmetic you run into theses pesky variables that gives students fits. Every one seems comfortable with 6+4 -(10÷2)=5. In general students have fewer problems with arithmetic and “order of operations” than they do with Algebra, The principal reason for this is the introduction of variables that are generally called “x”.

What is this business of “x”?

In math we encounter two types of quantities, constants and variables. Constants are numbers like 3, 5, 11, 1725. These numbers have a value that NEVER changes. Five will always be 5.

Variables, on the other hand change, can change their value depending on the circumstance. If we have a problem involving several unknown quantities then we can assign each unknown quantity its own variable. For example if there are three unknowns we can call them x, y, and z. To solve our problem we find the values for x, y and z that are meaningful for the particular problem.

Another aspect of Algebra that give students trouble is the concept of a function. In simple terms a function describes the relationship between variables. When we say y is a function of x we are talking about two variables and the relation between them. For example if you live in the United States you are accustomed to hearing the temperature given in degrees Fahrenheit. If you live elsewhere you are are probably accustomed to hearing the temperature given in degrees Celsius! There is a relationship between these two measures so that one can be converted to the other. This is an example of a function. Since I know the relationship I can find one given the other.

Lastly we introduce you to the “vocabulary” of math. There are certain key words that lead to a precise mathematical operation. For example it I have 5 oranges more than you, we can turn that into a mathematical expression. Even if I do not know exactly how many oranges you have, I can say that you have “x” oranges. In that case I will have “x + 5” oranges. Thus “more” translates to the mathematical operation “addition”.

What we are attempting to do is give you a brief introduction to the wonderful world of Algebra!!!!!