@stdlib/math-base-special-avercos (npm): Compute the inverse versed cosine.
Keywords: stdlib|stdmath|mathematics|math|avercos|avercosin|avercosine|arcvercos|arcvercosin|versed cosine|avercosinus|avcs|arc|versed|cosine|cos|acos|trig|trigonometry|radians|angle|javascript|node|node-js|nodejs|versed-cosine