code.java

import java.util.Scanner;
import java.lang.Math;
public class Derivative {
   public static void main(String[] args) {
      double product;
      String result;
      Scanner keyboard = new Scanner(System.in);
      int selection = 1;
      System.out.print("Hello! Welcome to Lucas's math solver! Your options for tools are as follows\n");
      while (selection != 0) {
         System.out.print("\t1. Derivative Finder\n\t2. Polynomial Factorer\n\t3. Circle Solver\n\t4. SSS Triangle Angle Finder\n\t0. End Program\n");
         selection = keyboard.nextInt();
         if (selection == 1) {
            System.out.print("Enter your coefficient of x:\n");
            double coefficient = keyboard.nextDouble();
            System.out.print("Enter the power of x as an integer:\n");
            int prepower = keyboard.nextInt();
            product = coefficient * prepower;
            int power = prepower - 1;
            if (prepower == 0) {
               System.out.print("The answer is 0\n");
               continue;
            }
            if (power != 0)
               System.out.print("The answer is " + product + "x^" + power + "\n");
            else
               System.out.print("The answer is " + product + "\n");
           }
           if (selection == 2) {
               char again;
               int a, b, c, canfactor;
               System.out.print("Enter the coefficient of x^2:");
               a = keyboard.nextInt();
               System.out.print("Enter the coefficient of x: ");
               b = keyboard.nextInt();
               System.out.print("Enter the constant: ");
               c = keyboard.nextInt();
               //0 is true
               canfactor = 0;
               double discriminant, temp, u, v;
               discriminant = (b * b) + (-4 * a * c);
               temp = (Math.sqrt(discriminant));
               u = (b + temp) / (2 * a);
               v = (b - temp) / (2 * a);
               if (discriminant < 0)
                  canfactor = 1;
               else {

                  if (temp * temp != discriminant)
                        canfactor = 1;
                  else {
                         if (((-b + temp) % 2) != 0 || ((-b - temp) % 2) != 0)
                           canfactor = 1;
                  }
               }
               if (canfactor == 0 && a == 1) {
                  temp = (int) (temp);
                  //these if statements just format the output so that the positive numbers get a + sign in front of them. The negatives already have a - sign, the they are in else statements.
                  if (b >= 0)
                        System.out.print("x^2 + " + b + "x");
                  else 
                        System.out.print("x^2 " + b + "x");
                  if (c >= 0)
                        System.out.print(" + " + c + "  factored is\n");
                  else 
                        System.out.print(" " + c + "  factored is\n");
                  System.out.print("(x ");
                  if (u >= 0)
                        System.out.print("+ " + u);
                  else 
                        System.out.print(u);
                  System.out.print(") (x ");
                  if (v >= 0) 
                        System.out.print("+ " + v);
                  else 
                        System.out.print(v);
                  System.out.print(")\n\n");
               //This simple code turns the values of x into their positives         then prints them out.
                  if (u > 0) 
                        u -= (2*u);
                  else if (u < 0) 
                        u += (-2*u);
                  if (v > 0) 
                        v -= (2*v);
                  else if (v < 0) 
                        v += (-2*v);
                  System.out.print("So, x is " + u + " and " + v + ".\n");
               }
               else if (canfactor == 0 && a != 1) {
                  System.out.println("X is " + -u + " and " + -v);
               }
               else
                  System.out.println("This is not factorable");
            }
            if (selection == 3) {
               System.out.print("This circle calculator uses pi rounded to 5 decimal places.\n");
               System.out.print("Please enter your circle's radius (P.S, if you only have the diameter, just divide that by 2):\n");
               double radius = keyboard.nextDouble();
               double area = 3.14159 * radius * radius;
               double circumference = 2 * 3.14159 * radius;
               System.out.print("The area of your circle is " + area + " units squared\n");
               System.out.print("And the circumference is " + circumference + " units\n");
            }
            if (selection == 4) {
               System.out.print("Hello, please enter the sides of your triangle, click enter when done!\n");
               System.out.print("Side 1: ");
               double a = keyboard.nextDouble();
               System.out.print("Side 2: ");
               double b = keyboard.nextDouble();
               System.out.print("Side 3: ");
               double c = keyboard.nextDouble();
               //this one finds angle a
               double anglea = ((b*b) + (c*c) - (a*a))/(2 * b * c);
               anglea = Math.acos(anglea);
               System.out.println("The angle opposite from side 1, " + a + ", is " + Math.toDegrees(anglea) + " degrees");
               
               //this one finds angle b
               double angleb = ((c*c) + (a*a) - (b*b))/(2 * c * a);
               angleb = Math.acos(angleb);
               System.out.println("The angle opposite from side 2, " + b + ", is " + Math.toDegrees(angleb) + " degrees");

               //this one finds angle c
               double anglec = ((a*a) + (b*b) - (c*c))/(2 * a * b);
               anglec = Math.acos(anglec);
               System.out.println("The angle opposite from side 3, " + c + ", is " + Math.toDegrees(anglec) + " degrees");
                           
             }      
      }
   
   }
}