Problem

Determine the different possibilities for the numbers of positive, negative, and nonreal complex zeros of the function
\[
f(x)=5 x^{4}+4 x^{2}+4 x-8
\]

The function $f(x)$ has 1 positive zero(s)
(Type a whole number.)
The function $f(x)$ has $\square$ negative zero(s)
(Type a whole number.)

Answer

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Answer

Final Answer: The function $f(x)$ has \(\boxed{1}\) negative zero and \(\boxed{2}\) nonreal complex zeros.

Steps

Step 1 :The function $f(x)$ is a polynomial of degree 4, so it has 4 zeros in the complex plane.

Step 2 :The zeros of a polynomial with real coefficients always come in conjugate pairs. Therefore, the number of nonreal complex zeros must be even.

Step 3 :We know that there is 1 positive zero.

Step 4 :There must be 1 negative zero to balance out the positive zero.

Step 5 :The remaining 2 zeros must be nonreal complex zeros.

Step 6 :Final Answer: The function $f(x)$ has \(\boxed{1}\) negative zero and \(\boxed{2}\) nonreal complex zeros.

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