Pre calculus consists of those subjects, skills, and insights which are necessary to recognize calculus. It involves arithmetic, algebra, coordinate Geometry, trigonometry, and, functions. In Pre calculus we study many different type of topics which includes, sets, real numbers, complex numbers, composite and polynomial Functions, trigonometry, limits, vectors, metrics, binomial theorem, and many other topics. Let’s understand few basic topic of pre calculus.

Set: - We know that Set is a collection of different type of objects which are defined in proper manner. Different types of operation are present in the set that are Union, intersection, complements and Cardinality product. Sets are of different type like Empty set, Universal set, etc.

If no element is available in the set then it is known as empty set, and the Sets are present in the universe of conversation are universal set.

Empty set is denoted by the symbol ‘∅’ and universal set is denoted by ‘U’

Real number: - In the Real Numbers all the Rational and Irrational Numbers and whole numbers are present.

For example: Whole numbers are (1, 4, 6, 8, 10). Sometime the number 0 is also involved in Whole Number.

Rational number – The Rational Numbers are 3/5, 0.16, 0.33…2.2 etc.

Irrational number – Irrational numbers are (⊼, √ 3) etc.

If we have √ -3, this number is not considered in the category of real number because it contains imaginary value and ‘∞’ and it is not a real number.

This is a brief introduction to Precalculus in which we come across few Basic Terms of pre calculus.