Question

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Answer 1

to find the number of *** possible *** positive real roots count the number of sign changes in the polynomial (how many times it changes from + to - or from - to +)

Answer 2

you have 2 sign changes so 2 possible positive roots

however, this might include complex positive roots so we must account for that by subtracting 2 from 2 to get 0

so there are two possibilities, two positive real roots or zero positive real roots + two imaginary positive roots

so 2 or 0 = your answer

Answer 3

got it