a = 1 (slider from -5 to 5)
k = 1 (slider from -5 to 5)
b = -1.1 (slider from -5 to 5)
h = 0 (slider from -5 to 5)
f(x) = (a * tan((k * x) - b)) + h
ec2: x = ((-pi)) / ((2 * k)) + b
ec1: x = pi / ((2 * k)) + b