# Give an example of an irrational number and how you mat use it or come across in the real world.

neela | High School Teacher | (Level 3) Valedictorian

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An irrational number is any real  number which can not be expressed in the form of p/q , where p and q are integers.The irrational are many and uncountable.

Some examples: e, pi and sqrt19.

We know e = Lt (1+1/x)^x as n--> infinity. The value of e is like 2.71828...

We know pi = Length of circumference of a circle/length of diameter of that circle. the value of pi is like 3.14159...

Square root 19. The value we know is between 4 and 5.

The knowledge of pi  is essential in geometry. It is used to know the length of circumference given the radius or diameter.

Rather than use , the invention of irrational number has contributed to the completeness of the idea of numbers. It gave a sense of enlightement that between any two distinct perfect square roots , there are still more square roots which need not be in p/q form alone.