Part a
Video is attached with narration
Part b
The purpose of my program is to help solve quadratic equations. I faced some difficulties along
the way as I pursued this purpose. For example, often times my solution methods were
returning “NaN”. I initially attempted to solve this by writing out the formula and making sure the
parentheses were grouped correctly. I ended up collaborating with one of my classmates to
determine why sometimes the solution was correct and other times it returned “NaN. I
determined that it returned “NaN” when the solutions were not real. After figuring out the
problem with the help of a partner, I independently learned about exceptions and how to “throw”
and “catch”. Using this new knowledge of exceptions, I was able to handle non-real solutions.
Initially, my problem was not user interactive. I learned about the Scanner class and saw the
opportunity to add a user interaction part to it to make it more friendly. I also saw many
opportunities to use abstraction such as when finding the solutions, I did not need to reprogram
the discriminant aspect of the quadratic formula. Instead, I just called the discriminant method of
my class.
Part c
public double getFirstSolution() {
double firstxsolution;
double discriminant = getDiscriminant();
if(discriminant<0) {
throw new IllegalArgumentException("The discriminant is negative. There
are no real solutions");
}
double root = Math.sqrt(discriminant);
firstxsolution = (-b + root)/(2*a);
return firstxsolution;
}
This is my algorithm to get the first solution of the quadratic equation. It works by using the
discriminant method of my class and using the Math class for some operations. First, I call the
getDiscriminant() method and store the value of b^2 - 4ac in a variable. This part of the
algorithm simplifies the rest of the calculations. It then checks if the discriminant is negative to
determine if the solutions are valid or not. If the solutions are invalid, it handles this by throwing
an exception. Otherwise, it calculates the square root of the discriminant using the Math class’
sqrt method. Then, it manipulates this square root value by adding it to negative b and dividing
the quantity by 2 * a, completing the quadratic formula. This algorithm is the primary algorithm
used in the program as the program’s intended purpose is to provide the solutions for a
quadratic equation. The mathematical concepts that it integrates are those of the square root
which is found using the Math.sqrt, unreal values which are accounted for in the if statement,
and the quadratic formula, which is the entire algorithm.
Part d
public double getDiscriminant()
{
double Discriminant = Math.pow(b, 2) - (4 * a * c);
return Discriminant;
}
Here is an example of an abstraction that I used in this program. I found that I often repeated
the procedure for finding a discriminant and that a user may even need to find only the
discriminant so I created a getDiscriminant() method in order to avoid repeating my code. This
method is not only called by both of the getSolution methods but also by the user if they need to
find the discriminant. It simplifies my code because it is easier to read when the getDiscriminant
method is called instead of the formula being written out. It also removes repetition. The method
works by using the Math class’s pow method to square the value of b. Then from that value, it
subtracts the quantity of 4ac which is the formula for the discriminant of a quadratic equation.
