क्षेत्र (field) &mathbb{Z}11[x] / ⟨x2 + 1⟩ में तत्वों की संख्या ज्ञात कीजिए।

In the polynomial ring &mathbb;Q[x], if f(x) = x3 + x2 + x + 1 and g(x) = x3 - x2 + x - 1, then the ideal ⟨f(x), g(x)⟩ generated by f(x) and g(x) is equal to:

Which of the following algebraic structures forms an Abelian group under the usual operation?