if a polynomial function f(x) has roots 0, 4, and , what must also be a root of f(x)?; what information must you have to write a polynomial function having all real roots given its graph?; if a polynomial function f(x) has roots 3 and , what must also be a root of f(x)? –3 3i; if a polynomial function f(x) has roots –9 and 7 – i, what must be a factor of f(x)?; if a polynomial function f(x) has roots 3 and sqrt 7 what must also be a root of f(x); which polynomial function could be represented by the graph below f(x)=x^2-6x+8; if a polynomial function f(x) has roots 3 sqrt 5 and -6, what must be a factor of f(x); if a polynomial function f(x) has roots –8, 1, and 6i, what must also be a root of f(x)?