Question

rezolvati in R ecuatia x²-|x| -2=0da sami explicati pasi care se vor face

Answer 1

IxI=x daca x≥0
     -x daca x<0
avem 2 cazuri
I caz daca x≥0 atunci IxI=+x
x²-IxI-2=0
x²-(+x)-2=0
x²-x-2=0
(x+1)(x-2)=0
x₁=-1
x₂=2
II caz daca x<0 atunci IxI=-x
x²-IxI-2=0
x²-(-x)-2=0
x²+x-2=0
(x+2)(x-1)=0
x₁=-2
x₂=1
x∈{-2,-1,1,2}