Question Number 165403 by naka3546 last updated on 01/Feb/22
$$\mathrm{sec}^{\mathrm{2}} \mathrm{1}°\:+\:\mathrm{sec}^{\mathrm{2}} \:\mathrm{2}°\:+\:\mathrm{sec}^{\mathrm{2}} \:\mathrm{3}°\:+\:\ldots+\:\mathrm{sec}^{\mathrm{2}} \:\mathrm{89}°\:=\:? \\ $$