What are the possible number of positive, negative, and complex zeros of f(x) = -3x4 + 5x3 - x2 + 8x + 4? (1 point)
Question 36 options:

1) Positive: 2 or 0; Negative: 2 or 0; Complex: 4 or 2 or 0

2) Positive: 1; Negative: 3 or 1; Complex: 2 or 0

3) Positive: 3 or 1; Negative: 1; Complex: 2 or 0

4) Positive: 4 or 2 or 0; Negative: 2 or 0; Complex: 4 or 2 or 0

Question

What are the possible number of positive, negative, and complex zeros of f(x) = -3x4 + 5x3 - x2 + 8x + 4? (1 point)
Question 36 options:
	
1) 	Positive: 2 or 0; Negative: 2 or 0; Complex: 4 or 2 or 0
	
2) 	Positive: 1; Negative: 3 or 1; Complex: 2 or 0
	
3) 	Positive: 3 or 1; Negative: 1; Complex: 2 or 0
	
4) 	Positive: 4 or 2 or 0; Negative: 2 or 0; Complex: 4 or 2 or 0

prepfortears · Answer

The 3rd choice. Do you want an explanation?

anonymous · Answer

yes @prepfortears

prepfortears · Answer

ok, plug -x in for x and look at signs$$f(x)=-3x^{4}-5x^{3}–x^{2}-8x+4 $$ thats ----+
1 sign change and 1 negative real

the original equation is -+-++
thats 3 sign changes and 3 positive reals or 1
so in the end you have (3 positive, 1 negative, and no complex) or (1 positive, 1 negative, and 2 complex)

prepfortears · Answer

any questions?