The exponential function, exp(x), calculates the value of e to the power of x, where e is the base of the natural logarithm, 2.718281828... .

By default, exp(x) will evaluate only when the result is an exact value, or when the input x is a floating-point number.  When x is a symbolic expression it will remain in function form so that it can be manipulated symbolically or as part of a larger expression.  

If x is an array, the result is an element-wise mapping over x.