# Determine positive/negative zeros using Descartes' rule of signs

Determine the possible number of positive and negative zeros of the following function by using Descartes' rule of signs.

f(x) = 5 + 4x - 5x^3

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#### Solution Preview

Descartes's rule of signs indicates that the number of positive real zeroes in a polynomial function f(x) is same, or less than by an even number, as the number of changes in the sign of the coefficients, and the number of negative real zeroes of this ...

#### Solution Summary

Solution step-wise explains how the possible zeros are determined for given function using Descartes' rule of signs.

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