FUNCIÓN EXPONENCIAL NATURAL
                    O DE BASE e

Para su representación gráfica 
construiremos una tabla de valores.

y = ℯ^x

a = 1 (slider from -5 to 5, step 0.1)
b = 1 (slider from -5 to 5, step 0.1)
c = 0 (slider from -5 to 5, step 0.1)
d = 0 (slider from -5 to 5, step 0.1)
f(x) = a exp(b x + c) + d