"cos⁻¹" meaning in Conventions internationales

{
  "categories": [
    {
      "kind": "other",
      "name": "Symboles en conventions internationales",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Conventions internationales",
      "orig": "conventions internationales",
      "parents": [],
      "source": "w"
    }
  ],
  "etymology_texts": [
    "De cos et de −1 en exposant, celui-ci signifiant une fonction réciproque."
  ],
  "lang": "Conventions internationales",
  "lang_code": "conv",
  "pos": "symbol",
  "pos_title": "Symbole",
  "related": [
    {
      "word": "sin⁻¹"
    },
    {
      "word": "tan⁻¹"
    },
    {
      "word": "cos"
    }
  ],
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Lexique en conventions internationales des mathématiques",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "Arc cosinus."
      ],
      "id": "fr-cos⁻¹-conv-symbol-X8JU-~ZY",
      "topics": [
        "mathematics"
      ]
    }
  ],
  "synonyms": [
    {
      "topics": [
        "mathematics"
      ],
      "word": "arccos"
    },
    {
      "topics": [
        "computing"
      ],
      "word": "acos"
    }
  ],
  "word": "cos⁻¹"
}

{
  "categories": [
    "Symboles en conventions internationales",
    "conventions internationales"
  ],
  "etymology_texts": [
    "De cos et de −1 en exposant, celui-ci signifiant une fonction réciproque."
  ],
  "lang": "Conventions internationales",
  "lang_code": "conv",
  "pos": "symbol",
  "pos_title": "Symbole",
  "related": [
    {
      "word": "sin⁻¹"
    },
    {
      "word": "tan⁻¹"
    },
    {
      "word": "cos"
    }
  ],
  "senses": [
    {
      "categories": [
        "Lexique en conventions internationales des mathématiques"
      ],
      "glosses": [
        "Arc cosinus."
      ],
      "topics": [
        "mathematics"
      ]
    }
  ],
  "synonyms": [
    {
      "topics": [
        "mathematics"
      ],
      "word": "arccos"
    },
    {
      "topics": [
        "computing"
      ],
      "word": "acos"
    }
  ],
  "word": "cos⁻¹"
}