Select the correct answer:

What is the completely factored form of this polynomial?

[tex]\[ x^4 + 12x^2 + 32 \][/tex]

A. [tex]\(\left(x^2 + 4\right)(x + 2)(x + 4)\)[/tex]

B. [tex]\(\left(x^2 + 4\right)\left(x^2 + 8\right)\)[/tex]

C. [tex]\((x + 4)(x + 8)\)[/tex]

D. [tex]\((x + 2)(x - 2)\left(x^2 + 8\right)\)[/tex]



Answer :

To factor the polynomial [tex]\( x^4 + 12x^2 + 32 \)[/tex] completely, we can follow these steps:

1. Identify the Structure of the Polynomial:
Observe that the polynomial [tex]\( x^4 + 12x^2 + 32 \)[/tex] can be thought of as a quadratic in terms of [tex]\( x^2 \)[/tex]. That is, let [tex]\( y = x^2 \)[/tex]. This transforms the polynomial into:
[tex]\[ y^2 + 12y + 32 \][/tex]

2. Factor the Quadratic Expression:
Next, we need to factor [tex]\( y^2 + 12y + 32 \)[/tex] into two binomials. We look for two numbers that multiply to 32 and add up to 12. These numbers are 4 and 8. Hence, we can rewrite the quadratic as:
[tex]\[ y^2 + 12y + 32 = (y + 4)(y + 8) \][/tex]

3. Substitute Back [tex]\( y = x^2 \)[/tex]:
Now, re-substitute [tex]\( y \)[/tex] with [tex]\( x^2 \)[/tex]:
[tex]\[ (y + 4)(y + 8) \rightarrow (x^2 + 4)(x^2 + 8) \][/tex]

4. Conclusion:
Therefore, the completely factored form of the polynomial [tex]\( x^4 + 12x^2 + 32 \)[/tex] is:
[tex]\[ (x^2 + 4)(x^2 + 8) \][/tex]

5. Select the Correct Answer:
Among the given options, the correct one is:
[tex]\[ \boxed{(x^2 + 4)(x^2 + 8)} \][/tex]