(A) 1

(B) 3

(C) 4

(D) 5

(E) 2

Solution:

x^6 –12(x^4) + 32(x^2) = x^2 (x^4 – 12x^2 + 32) = x^2 (x^2 – 4)(x^2 – 8)

The roots are 0, ±2, and ±2√2: a total of 5.

Please remember that ‘0’ is also a root.

The correct answer is D

Labels: Equations, factorizing, factors, powers, roots