Given the exponential function a(x)=p(1+r)^x, what value for r will make the function a decay function

The function will be a decay function for
.. |1 +r| < 1
.. -1 < 1 +r < 1
.. -2 < r < 0

Any value of r in the interval (-2, 0) will make the function a decay function.


If x can have non-integer values, then you probably want r ∈ (-1, 0).

The answer is 10 bud