There is a unique polynomial P(x) of degree 4 with rational coefficients and leading coefficient 1 which has sqrt(1 + sqrt(6)) as a root. What is P(1)?
Based on the information provided: P(x) = x^4 + ax^3 + bx^2 + cx + d
P(1) = 1 + a + b + c + d
After a bit of educated guessing, it seems this polynomial would be (x+√1+√6)(x+√1−√6)(x−√1+√6)(x−√1−√6)
Which simplifies to x4−2x2−5
I'm not entirely sure why this works, but I think it's because it can be turned into a quadratic by setting y=x^2 (and the square roots must cancel out). Anyone?
Aside from that, 1-2-5 = -6.