Tracer la droite d

f(x) = exp(x)
B = (2, -1)
a = 1.76 (slider from -2 to 2, step 0.01)
M: (a, f(a))
b = Segment(M, B)
d = OrthogonalLine(M, b)
distanceMB = Distance(M, B)
TexteMB: Name[M] + (Name[B]) + " \, = \, " + distanceMB
d_1 = false