What is arbitrary real number? explain in brief plzzzzzz..........

a number which could be any number it is defined to be, i.e, it can take any value, but  for which no specific value is chosen... for eg;  alpha and beeta are arbitraray real numbers which can take any value.

another example is of theta and phi, which can take the value of  any real number.

hope it is clear to you and i have tried to explain..............