Question

consideram functia f:R->, f(x)=x√2-3 si multimea A={f(-1);f(0);f(√2)}. Determinati A inclus Q.Va rog frumos sa ma ajutati!!!

Answer 1

f(-1)=-1*√2-3=-√2-3 ∉Q
f(0)=0*√2-3=-3 ∈Q
f(√2)=√2*√2-3=2-3=-1∈Q

A={-3 ,-1}