Let g(x) be the monic polynomial?
whose roots are a+b, a+c, and b+c (each with multiplicity 1). Determine g(x).
sum of the roots = - coefficient of x^2
hence
a + b + c = -2
So a+b = -2-c
a +c = - 2-b
b+c = - 2- a
so we need to find equation whose roots are 2-a, 2-b 2-c
p(x)=x^3+2x^2+3x+4 has roots a,b,c
so p(-x) = -x^3 + 2x^2 – 3x + 4
or f(x) = x^3 – 2x + 3x – 4 (dividing p(-x) by – 1) has roots –a , -b ,- c
so f(x+2) = (x+2)^3 – 2(x+2)^2 + 3(x+2) – 4 has roots -2 – a , -2 –b , -2 - c
so g(x) = f(x+ 2) = x(x+2)^2 + 3 x+ 6- 4
= x(x^2 + 4x+ 4)+ 3x + 6 -2
= x^3 + 4x^2 + 7x + 4 is the required result.
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