Given
and
find
The answer in the book shows:
first of all, the functions you posted as f(x) and g(x) do not work out to the desired result ... sure you posted the correct f(x) and g(x)? If f(x) = x+1 and g(x) = x-1, then (f+g)(x) = (x+1) + (x-1) = 2x
What I don't understand is why is it x^2 - x + 1 and not x^2 - 1 + x?
This can easily be explained ... it's just standard notation for a polynomial. x<sup>2</sup> - x + 1 = x<sup>2</sup> - 1 + x (you "see" that fact, correct?) ... normally, polynomials are written in what is called "decreasing" order of degree (degree is the value of the exponent) ... highest first, then the next lower exponent, right on down to the constant.
x<sup>2</sup> - x - 1 is really x<sup>2</sup> - x<sup>1</sup> - 1x<sup>0</sup> ... see how the exponents decrease in order?