k = 1.3 (slider from 0 to 10, step 0.1)
f(x) = exp(k x)
g(x) = exp(-k x)
M = Point(f)
A = Intersect(f, yAxis, (0, 1))
a = Line(M, yAxis)
N = Intersect(g, a, (0.9650000000000002, 0.28521842178898654))
P = Intersect(a, xAxis)
b = Tangent(M, f)
c = Tangent(N, g)
M' = Intersect(b, xAxis)
N' = Intersect(c, xAxis)