Translate ADT into java interface example 4

Problem:

Translate this ADT into a Java interface:
ADT: Polynomial
degree(): int
derivative(): Polynomial
equals(Point): Boolean
sum(Polynomial): Polynomial
toString(): String
valueAt(Real): Real

Output:

None

Solution:

public interface Polynomial {
 public int degree();
 public Polynomial derivative();
 public boolean equals(Object object);
 public Polynomial sum(Polynomial polynomial);
 public String toString();
 public double valueAt(double x);
}