e^iφ

cos φ

sin φ

r1: y^(2) + x^(2) = 1
A = Point(r1)
kx = OrthogonalLine(A, xAxis)
B = Intersect(kx, xAxis)
O = Point({0, 0})
p = Segment(O, A)
c = Segment(O, B)
s = Segment(B, A)
C = Point(xAxis)
φ = Angle(C, O, A)
text1: "e^{iφ}= cos φ + i·sin φ = " + (LaTeX[c]) + " + i·" + (LaTeX[s]) + ""
t(x) = x - x^(3) / 3! + x^(5) / 5! - x^(7) / 7!
f(x) = sin(x)