Question

Пусть f(x+3)=x в квадрате + 4x + 5. Найти f(x)

Answer 1

f(x+3) = x^2 + 4x + 5

x+3 = t

x = t-3

f(t) = (t-3)^2 + 4(t-3) + 5 = t^2 - 6t + 9 + 4t - 12 + 5 = t^2 - 2t + 2

f(x) = x^2 - 2x + 2