Question

13. Se consideră funcţiaf: R → R, f(x) = 2x – 1. Rezolvați ecuațiile:
b) f(x) = x;
c) f (x + 1) = x² -2.
a) f(x) = 0​

Answer 1

a)2x-1=0
2x=1 => x=1/2
b)2x-1=x
2x-x=1 => x=1
c)(2x-1)(x+1)=x^2-2
(2x^2-2x-x-1)=x^2-2
2x^2-3x-1=x^2-2
2x^2-x^2=-3x=-1+2
x^2-3x+1=0
x^2-2x-x+1=0
x(x-1)(x-1)=0
x(x-1)^2=0
x=0
x-1=0
x=1
f(1)=-2
f(2)=-1