Question

show that polynomial x4+4x2+5 has no zero

Answer 1

what is your questions?

Answer 2

5 has 4 factors 1,-1,5,-5
Since all signs in the polynomial are positive, we cannot apply 1 and 5.
When we apply -1 and -5 in place of x, the answer does not come zero.
Therefore, the given polynomial has no zero.

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