Question

va rog un ex Fie f;R-R,f[x]=-x√2+1 si multimeaA=[f[-2√2]; f[-2];f[0]; f[1]; f[√2] Determinati A INCLUDE N

Answer 1

f(x) = -x√2 +1

f(-2√2) = -(-2√2) ×√2 +1= 2√2×√2 +1 = 4+1= 5        5 ∈ N
f(-2)  = -(-2) ×√2 + 1 = 2√2 +1    ∉ N
f(0)  = 0 ×√2 + 1 = 1           1 ∈  N
f(1)  = -1 ×√2 +1 = -√2 +1       ∉ N
f(√2) = -√2 ×√2 +1 = -2 +1 = -1      ∉  N
⇒A ={1;5}