N-CN.C. Use complex numbers in polynomial identities and equations.

N-CN.C.7. Solve quadratic equations with real coefficients that have complex solutions.

• Completing the square

N-CN.C.8. Extend polynomial identities to the complex numbers. For example, rewrite $x^2 + 4$ as $(x + 2i)(x - 2i)$.

• Complex Cube and Fourth Roots of 1

N-CN.C.9. Know the Fundamental Theorem of Algebra; show that it is true for quadratic polynomials.

• No tasks yet illustrate this standard.