REVIEW OF MATHEMATICS

SYMBOLS, SCIENTIFIC NOTATION, AND SIGNIFICANT FIGURES

It is important that you learn to use symbols, rather than numerical values, in doing calculations. Letters near the end of the alphabet, such as x, y and z, are used for unknown variables. Letters such as a, b, and c are often used for given constant quantities. Greek letters are used for angular variables. Subscripts are used to provide added information. For example, the position of an object at time t1 I label as x1, and its position at time t2 is x2. Commonly encountered symbols are listed below :

a = b means a is equal to b.
a ¹ b means a is not equal to b.
a > b means a is greater than b, and a ≥ b means a is greater
than or equal to b.
a >> b means a is much greater than b.
a < b means a is less than b, and a ≤ b means a is less than
or equal to b.
a << b means a is much less than b.
a µ b means a is proportional to b.
a @ b means a is approximately equal to b.

n! = 1 · 2 · 3 · 4 · · · n
y (x) means the quantity y depends on the value of x ; that is, y
is a function of x .
∑i xi = x1 + x2 + x3 + · · · + xn .