State the number of positive real zeros, negative real zeros, and imaginary zeros for g(x)=9x^3-7x^2+10x-4.
Descartes Rule can help you.
g(x) = 9x^3 - 7x2 + 10x - 4
+ - + - Notice the signs
the signs varies 3 time + -, - +, + - therefore there are 3 variations
That means that there are 3 possible positive real zeros or 1 positive
real zeros
Now
g(-x) = 9(-x)^3 - 7(-x)^2 + 10(-x) - 4
= -9x^3 + 7x^2 - 10x - 4
= - + - - Notice the signs
The signs varies 2 times - +, + - therefore there are 2 variations
that means that there are 2 possible negative zeros
With the given variations the possible zeros are:
3 positive real zeros, 0 negative real zeros, 0 imaginary
or
1 positive real zeros, 2 negative real zeros, 0 imaginary
Remember that the highest degree x^3 determines the number of zeros you have
so each total possible zeros are 3
I hope this help