f(x) = sin(0.7 * x) + 3
F = Point(xAxis)
c = OrthogonalLine(F, xAxis)
A = Intersect(f, c, (1.3179311774764446, 3.79714497451476))
a = Tangent(A, f)
B = Point(a)
C = Point(a)
D = Point(a)
b = Segment(B, C)
k = Slope(b)
e: x(F)
d = Vector(F, A)
teksti1: "DERIVAATTA    f ' (" + e + ")  =  " + k