The polynomial equation x(x2 + 4)(x2 - x - 6) = 0 has how many real roots?
Solution:
Given the polynomial:
x(x2 + 4)(x2 - x - 6 ) = 0
Equating each term to zero
x = 0 which is a real root
x2 + 4 = 0
(x + 2i)(x - 2i) = 0
x = 2i,-2i which are two imaginary roots
(x2 - x - 6) =0
x2 - 3x + 2x - 6 = 0
x(x - 3) + 2(x - 3) = 0
(x + 2)(x - 3) = 0
x = -2,3 which are two real roots
Hence, the equation has 3 real roots.
The polynomial equation x(x2 + 4)(x2 - x - 6) = 0 has how many real roots?
Summary:
The polynomial equation x(x2 + 4)(x2 - x - 6) = 0 has 3 real roots.
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