How do you find all the zeros of F (x) = 5x^3 (x+ 3)^ 4 (x-7)F(x)=5x3(x+3)4(x7) with all its multiplicities?

1 Answer
Aug 20, 2017

The zeros are:

x=0" "x=0 with multiplicity 33

x=-3" "x=3 with multiplicity 44

x=7" "x=7 with multiplicity 11

Explanation:

  • Each linear factor corresponds to a zero. That is: aa is a zero if and only if (x-a)(xa) is a factor.

  • The multiplicity of each factor is the multiplicity of the corresponding zero.

We can rewrite the given F(x)F(x) slightly to bring it into a form with factors with the form (x-a)(xa) as follows:

5x^3(x+3)^4(x-7) = 5(x-0)^3(x-(-3))^4(x-7)5x3(x+3)4(x7)=5(x0)3(x(3))4(x7)

So the zeros are:

x=0" "x=0 with multiplicity 33

x=-3" "x=3 with multiplicity 44

x=7" "x=7 with multiplicity 11