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Make a table showing the possible numbers of positive real zeros, negative real zeros, and imaginary zeros for the function

Make a table showing the possible numbers of positive real zeros, negative real zeros-example-1
User Nduplessis
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Using Descartes' Rule of Signs, the function f(x)=2x^5-5x^3+2x-6 could have 2 or 0 positive real zeros, 1 or 0 negative real zeros, and the remaining zeros would be imaginary. The total number of zeros for a fifth-degree polynomial is 5.

To determine the possible number of positive real zeros, negative real zeros, and imaginary zeros for a polynomial function, we can use Descartes' Rule of Signs.

For the function f(x)=2x^5-5x^3+2x-6, we need to count the number of sign changes in the polynomial to predict the number of positive real zeros.

Similarly, we replace x with -x to find the number of negative real zeros. Imaginary zeros occur in conjugate pairs, therefore, the number of imaginary zeros is always even.

For the positive real zeros, f(x) has two sign changes, which means it can have 2 or 0 positive real zeros.

For the negative real zeros, f(-x)=2x^5+5x^3-2x-6 has one sign change, indicating 1 or 0 negative real zeros.

Lastly, the function is a fifth-degree polynomial, meaning it has a total of 5 zeros.

The number of imaginary zeros can be found by subtracting the total number of real zeros from 5.

If there are three real zeros (either positive or negative), there would be 2 imaginary zeros; if there are two real zeros, there would be 3 imaginary zeros, and so on.

The probable question may be:

Make a table showing the possible numbers of positive real zeros, negative real zeros, and imaginary zeros for the function. f(x)=2x^5-5x^3+2x-6

User Aeijdenberg
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