Question

Fie f:R->R, f(x)=3x+m. Determinati m∈R pentru care (f·f)(1)=14.

Answer 1

[tex]f(1)=3+m\\ f(f(1))=14\\ f(3+m)=14\\ 3(3+m)+m=14\\ 9+3m+m=14\\ 4m=5\\ m= \frac{5}{4} [/tex]