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УСЛОВИЕ:
Найдите первый член и знаменатель геометрической прогрессии, если b2=6 b4=2/3


РЕШЕНИЕ:

(Bn) геометрическая прогрессия             Bn(в квадрате)=Bn-1 * Bn+1 (свойство г. п)

B2=2                                                       B3( в квадрате)=6 * 2/3

B4=2/3                                                    B3(в квадрате)=4

q-                                                          B3=2

B1-                                                        q=Bn+1/Bn

                                                              q=B3/B2

                                                               q= 2/6

                                                              q=1/3

                                                               B2=B1*q

                                                               B1=B2/q

                                                               B1=6/ 1/3= 6*3=18

 

                                                            






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