При каких значениях Х,выражение √х²-8х+15 не имеет смысла

y(x)=√(x²-8x+15) не имеет смысла, если x²-8x+15<0                                                                    (x+3)(x+5)<0                                                   +                             -                              +                                     ______________-5_______________-3_________                                                                  x∈(-5;-3)