If -2 is a root of f, then (x-(-2))=(x+2) is a factor of f
similarly, if 5 is a root of f, then (x-5) is a factor of f(x).
These roots have multiplicity 2 means that there are 2 of each,
so f(x) is written as (x+2)(x+2)(x-5)(x-5)
[tex]f(x)= (x+2)^{2} (x-5)^{2} [/tex]
[the most general form is f(x)= c*(x+2)^{2} (x-5)^{2}*P(x), where c is a constant and P(x) another polynomial]
To show that -2 and 5 are zeros of f, we must prove that f(-2)=0 and f(5)=0,
Using the function we wrote:
[tex]f(-2)= (-2+2)^{2} (-2-5)^{2}=0* (-7)^{2}=0[/tex]
similarly:
[tex]f(5)= (5+2)^{2} (5-5)^{2}=0 [/tex]