Given 2 m r [i cos r2 – sin r2] = dx/dr
Separate variables 2 m r dr [i cos r2 – sin r2] = dx
Divide both sides by m 2 r dr [i cos r2 – sin r2] = dx/m
Express each side as an integral ∫ 2 r dr [i cos r2 – sin r2] = ∫ dx/m
Integrate cos r2 + i sin r2 + c1 = x/m + c2
Subtract c2 from both sides cos r2 + i sin r2 + c1 – c2= x/m
c1 – c2 = c2 for some c cos r2 + i sin r2 + c2 = x/m
Multiply both sides by m m [cos r2 + i sin r2] + m c2= x
E = m c2 m [cos r2 + i sin r2] + E = x
Subtract E from both sides m [cos r2 + i sin r2] = x – E
De Moivre’s rule: exp (ø i) = cos ø + i sin ø m exp (r2 i) = x – E
E (work) = force . distance m exp (r2 i) = x – F.s
F (force) = mass times acceleration m exp (r2 i) = x – mas
r2 = rr m exp (rri) = x – mas
exp (a) = ea m erri = x – mas
(Apparently originated with Brett Stevens, “Seasonal Greeting,” in the New Scientist, 21-28 December 1991)