# Calculate parasite drag coefficient from drag polar

The drag polar of an electric-powered unmanned aircraft is

$$C_D = 0.038 + 0.0458 C_L^2$$

What is the parasite drag coefficient?

Well, $$C_D = C_{D,0} + k_1 C_L^2 + k_2 C_L$$ according to Brandt et al's "Introduction to Aeronautics: A Design Perspective," so the parasite drag coefficient is $$C_{D,0}$$ or 0.038.
(Also, $$k_1 = 0.0458$$ and $$k_2 = 0$$.)