Question

which of the following quartic functions has x=-1 and x=-2 as its only two real zeros?

x^4-3x^3+3x^2-3x+2
x^4+3x^3+3x^2-3x-2
x^4+3x^3+3x^2+3x+2
x^4-3x^3-3x^2+3x+2

Answer 1

x^4 - 3x^3 + 3x^2 - 3x + 2

x = 1 and x = 2

 

x^4 + 3x^3 + 3x^2 - 3x - 2

x = -0.5147 and x = 0.8516

 

x^4 + 3x^3 + 3x^2 + 3x + 2 so this function is the answer

x = -2 and x = -1

 

x^4 - 3x^3 - 3x^2 + 3x + 2
x = - 1  x= 1