assertTrue(a.getComplex(0).equals(new Complex(1.5, 8.75)));
assertTrue(a.getComplex(1).equals(new Complex(3, 4)));
assertTrue(a.getComplex(2).equals(new Complex(5, 6)));
// testing subtract(int, double, double, int)
a.subtract(0, 1.5, -4.75, 2);
assertTrue(a.getComplex(0).equals(new Complex(-3.5, -10.75)));
assertTrue(a.getComplex(1).equals(new Complex(3, 4)));
assertTrue(a.getComplex(2).equals(new Complex(5, 6)));
// testing subtract(int, double, double, double, double)