Question

Să se determine punctele de interacție ale graficelor f, g:R-R, f(x) =x^2-3x-1,g(x) =x+4. b.) f(x) =-x+1,g(x) =3x^2-3x+1

Answer 1

a) f(x) = g(x) => x^2-3x-1 = x+4
x^2-4x-5 = 0
delta = 36
x1 = 5 => f(5) = 9; g(5) = 9 => A(5,9)
x2 = -1 => f(-1)=3; g(-1) = 3 => A(-1;3)

b) f(x) = g(x) => 3x^2 - 3x +1 = -x+1
3x^2-2x = 0
delta = 4
x1 = 2/3 => f(2/3) = 1/3 => B(2/3, 1/3)
x2= 0 => f(0) = 1 => B(0, 1)