you don't have a zero exponent in math.
A rational exponent is an exponent in the form of a fraction. Many financial formulas use rational exponents. Compound interest is formula that uses rational exponents.
the exponent is a negative
No, it is an expression, not an equation.
You can use any number - rational or otherwise - as an exponent.
And exponent of -2 represents the square root
Rational, since it can be written as 25/1 .
1.57 is rational.
it means that it is something about math