Expert Answers

An illustration of the letter 'A' in a speech bubbles

I believe that your basic question is the difference between a variable and a parameter.

Many math instructors are rather loose with the vocabulary; in particular they will define a variable as a letter/symbol taking the place of a number. But there is a difference between a physical constant, a constant, a parameter, and a variable.

A physical/mathematical constant is a number that arises in particular applications so often that we represent it with a letter/symbol. Thus `pi,phi` in math, or c for the speed of light, etc... are constants.

Other constants aren't as prevalent or have a specific utilization. Specific substances have a specific boiling point, measure of elasticity, albedo, etc...

A variable is allowed to change within the application/procedure/algorithm. Thus we are allowed to change "x" in an algebraic equation and "y" will then possible change.

A parameter does not change in a specific application, but takes on different values from application to application. Pythagoras's theorem `a^2+b^2=c^2` applies to all right triangles, but are unchanged if you are give a specific triangle.

A good example of parameters at work is the equation for a parabola. `y=ax^2+bx+c` ; for a specific parabola a,b, and c remain unchanged while x and y are allowed to change.

See eNotes Ad-Free

Start your 48-hour free trial to get access to more than 30,000 additional guides and more than 350,000 Homework Help questions answered by our experts.

Get 48 Hours Free Access
Approved by eNotes Editorial