The polynomial has a degree of , whose coefficients are real numbers.

Its zeros are and .

By corollary theorem:

The polynomial of third degree with real coefficients must have one real zero.

The polynomial with third degree must have one real zero.

By conjugate pairs theorem:

If is a zero of the polynomial then is also be the zero of the function.

Hence the polynomial has four zeros.

Therefore statement is contrdictory.

The statement is contrdictory.