Question

Dada a função y = x² + 2x -13, determine o numero real x cuja imagem pela funçao é 22.

Answer 1

Nathalia,

 A imagem é o valor da função
 Então
                       22 = x² + 2x - 13
                               x² + 2x - 13 - 22 = 0
                               x² + 2x - 35 = 0
                  fatorando
                                     (x + 7)(x - 5) = 0
                                          x + 7 = 0
                                                            x1 = - 7
                                          x - 5 = 0
                                                            x2 = 5
                                                                             Im = - 7 ou 5