quadratic Eq. How to solve

Author: ostad-ai

README.md

@@ -2,4 +2,5 @@
 
 1) Lists: Introduction
 2) Lists: Example, computing Khayyam-Pascal's triangle
-3) Lists: Copying
+3) Lists: Copying
+4) Exercise: Solving quadratic equation

quadratic equation-how to solve.ipynb

@@ -0,0 +1,97 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Python: Everything\n",
+    "- 4) Example: Solving Quadratic equation\n",
+    "<br>----------------------------------------------\n",
+    "<br> By Hamed Shah-Hosseini\n",
+    "<br> https://github.com/ostad-ai/Python-Everything"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "Quadratic equation: $ax^{2}+bx+c=0$ <br> is solved by: $x=\\frac{-b\\pm\\sqrt{b^{2}-4ac}}{2a}$"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 8,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "from math import sqrt\n",
+    "\n",
+    "def quadratic(x,a,b,c):\n",
+    "    return a*x**2+b*x+c\n",
+    "\n",
+    "def solveQ(a,b,c):\n",
+    "    x=[None]*2\n",
+    "    if a==0:\n",
+    "        if b!=0:\n",
+    "            x[0]=x[1]=-c/b\n",
+    "    else:\n",
+    "        delta=b**2-4*a*c\n",
+    "        if delta>=0:\n",
+    "            temp=sqrt(delta)\n",
+    "            x[0]=(-b+temp)/(2*a)\n",
+    "            x[1]=(-b-temp)/(2*a)\n",
+    "    return x"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 13,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "solutions:  -3.0 -5.0\n"
+     ]
+    }
+   ],
+   "source": [
+    "a,b,c=[1,8,15]\n",
+    "x=solveQ(a,b,c)\n",
+    "if x[0] is None:\n",
+    "    print('No real solution')\n",
+    "else:\n",
+    "    print('solutions: ',x[0],x[1])"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": []
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.8.3"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 5
+}