Use the given zero to find all the zeros of the function, Please explain I do not understand?
Given zero: 3i
(The i is imaginary)
Function: f(x)=x³+x²+9x+9
Given zero: 3i
(The i is imaginary)
Function: f(x)=x³+x²+9x+9
1 Answer
Explanation:
The zeros, or roots, of a function
This problem uses two properties of roots.

#x_0# is a zero of a polynomial#P(x)# if and only if#(xx_0)# is a factor of#P(x)# . 
If
#P(x)# is a polynomial with real coefficients and#z=a+bi# is a nonreal complex number which is a zero of#P(x)# , then its complex conjugate#bar(z)=abi# is also a zero of#P(x)# .
As
Because
As
#=c(x^2+9)(xx_0)#
#=cx^3cx_0x^2+9cx9cx_0#
Finally, we equate coefficients to find the unknown values. Equating the coefficients of the
So, all together,