quad-solver

Solve quadratic equations of the form ax² + bx + c = 0 — via CLI or REST API.

Installation

Global — to use the CLI from anywhere:

npm install -g quad-solver

Local — to run the API server in a project:

npm install quad-solver

CLI

quad-solver <a> <b> <c>

Solves ax² + bx + c = 0 and prints the result.

Examples

quad-solver 1 -5 6
# { roots: [ 3, 2 ], discriminant: 1 }

quad-solver 1 -2 1
# { roots: [ 1 ], discriminant: 0 }

quad-solver 1 0 1
# { roots: 'no real roots', discriminant: -4 }

REST API

Start the server:

npx quad-solver-server
# or, if installed locally:
npm start

Server runs on http://localhost:3000 by default.
Set a custom port with the PORT environment variable:

PORT=4000 npm start

POST /solve

Request

POST /solve
Content-Type: application/json

{
  "a": 1,
  "b": -5,
  "c": 6
}

Responses

| Case | roots | discriminant | | ------------------ | ----------------- | -------------- | | Two distinct roots | [3, 2] | > 0 | | Double root | [1] | 0 | | No real roots | "no real roots" | < 0 |

Example with curl:

curl -X POST http://localhost:3000/solve \
  -H "Content-Type: application/json" \
  -d '{"a": 1, "b": -5, "c": 6}'

{ "roots": [3, 2], "discriminant": 1 }

Error (400) — when a, b, or c is missing:

{ "error": "Provide a, b, and c in the request body." }

API Reference

solve(a, b, c)

The core function exported by this package.

import { solve } from "quad-solver";

solve(1, -5, 6); // { roots: [3, 2],          discriminant: 1  }
solve(1, -2, 1); // { roots: [1],             discriminant: 0  }
solve(1, 0, 1); // { roots: 'no real roots', discriminant: -4 }

| Parameter | Type | Description | | --------- | -------- | ----------------- | | a | number | Coefficient of x² | | b | number | Coefficient of x | | c | number | Constant term |

Returns:

{
  roots: number[] | "no real roots",
  discriminant: number
}

Throws Error if any coefficient is not a finite number.

Author

Temiloluwa Tomilola David [Mac]

License

MIT