// method in adding Polynomials that will return c = a + b

public Polynomial add(Polynomial b) {

Polynomial a = this;

Polynomial c = new Polynomial(0, Math.max(a.deg, b.deg));

for (int i = 0; i <= a.deg; i++) c.coef[i] += a.coef[i];

for (int i = 0; i <= b.deg; i++) c.coef[i] += b.coef[i];

c.deg = c.degree();

return c;

}

//method in subracting Polynomials that will return c = (a - b)

public Polynomial subtract(Polynomial b) {

Polynomial a = this;

Polynomial c = new Polynomial(0, Math.max(a.deg, b.deg));

for (int i = 0; i <= a.deg; i++) c.coef[i] += a.coef[i];

for (int i = 0; i <= b.deg; i++) c.coef[i] -= b.coef[i];

c.deg = c.degree();

return c;

}

//method in Multiplying Polynomails that will return c = (a * b)

public Polynomial multiply(Polynomial b) {

Polynomial a = this;

Polynomial c = new Polynomial(0, a.deg + b.deg);

for (int i = 0; i <= a.deg; i++)

for (int j = 0; j <= b.deg; j++)

c.coef[i+j] += (a.coef[i] * b.coef[j]);

c.deg = c.degree();

return c;

}

-Just want to ask whats the purpose of Polynomial a = "this" <--- why this .