Question

va rog, ajutor !
50 de puncte !
dau coroana !​

Answer 1

Răspuns:

Explicație pas cu pas:

1) a) f:A ----> {4 , 3 , 2 , 1 , 0 , -1}  ; f(x) = -x+1

f(x) = 4  => -x+1 = 4  => x = 1-4  => x = -3

f(x) = 3  => -x+1 = 3 => x = 1-3 => x = -2

f(x) = 2 => -x+1 = 2 => x = 1-2 => x = -1

f(x) = 1 => -x+1 = 1 => x = 0

f(x) = 0 => -x+1 = 0 => x = 1

f(x) = -1 => -x+1 = -1 => x = 2

A = {-3 ; -2 ; -1 ; 0 ; 1 ; 2}

b) f: A ---> {0 , 4 , 9 , 16} ; f(x) = x²

f(x) = 0 => x² = 0  => x = ±√0  => x = 0

f(x) = 4  => x² = 4  => x = ±√4  => x = -2 ; x = 2

f(x) = 9 => x² = 9  => x = ±√9 => x = -3 ; x = 3

f(x) = 16 => x² = 16  => x = ±√16 => x = -4 ; x = 4

A = {-4 ; -3 ; -2 ; -1 ; 0 ; 1 ; 2 ; 3 ; 4}