Find the expression of a polynomial function of degree 3 with the following characteristics: zeros:3,i,-i, goes through point (1,-4)

p(x)=a(x-3)(x-i)(x+i) 


p(x)=a(x-3)(x^2+1) 


p(1)=-4 means 


-4=a(1-3)(1^2+1)


-4=a(-2)(2) 


a=1 


p(x)=1(x^3-3x^2+x-3) 


p(x)=x^3-3x^2+x-3 

:)