curl --request POST \
  --url https://api.iotools.cloud/v1/tool/vertex-axis-calculator \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "coeffA": "1",
  "coeffB": "-4",
  "coeffC": "3"
}
'

{
  "tool": "vertex-axis-calculator",
  "tool_version": "1.0.2",
  "outputs": {
    "vertex": "(2, -1)",
    "axisOfSymmetry": "x = 2",
    "direction": "Upward",
    "vertexType": "Minimum",
    "discriminant": "4",
    "roots": "x₁ = 3, x₂ = 1",
    "standardForm": "y = x² - 4x + 3",
    "vertexForm": "y = (x - 2)² - 1",
    "steps": "y = x² - 4x + 3, with a = 1, b = -4, c = 3\nAxis of symmetry: x = −b / (2a) = 4 / 2 = 2\nVertex y-coordinate: k = c − b² / (4a) = 3 − 16 / 4 = -1\nVertex: (h, k) = (2, -1)\nVertex form: y = (x - 2)² - 1\nSince a > 0, the parabola opens upward and the vertex is a minimum.\nDiscriminant: Δ = b² − 4ac = 4\nΔ > 0 → two real x-intercepts: x₁ = 3, x₂ = 1"
  },
  "credits_used": 5,
  "credits_remaining": null
}