a = 2.1001 (slider from 1.0E-4 to 5, step 0.1)
b = 2.901 (slider from 0.0010 to 10, step 0.1)
c = 0.6 (slider from -5 to 5, step 0.1)
d = 0.2 (slider from -5 to 5, step 0.1)
e = -1.5 (slider from -5 to 5, step 0.1)
f(x) = a * b^(c * x + d) + e