You can write the cosine of an angle as a power series. cos x = 1-x²/2!+x⁴/4!-x⁶/6!+…. With every term, the series looks more like the cosine. I plotted the first 36 terms from -4π to 4π.

Cosine power, white on black, A3

• A3, 40 x 27 cm