256 Bài tập Hàm số mũ và Logarit cực hay có lời giải chi tiết (P3)

Đặt a= log 7 11, b=log 2 7 Hãy biểu diễn log (căn bậc 3 của 7) 121/8

28/50

Đặt a=log711,b=log27 Hãy biểu diễn log731218 theo a và b.

xuI6GyF5JsxpdC6BUNMWD5ENBNDMmj1wpeBwjJx7IUYZUzCbVJu2m-72m12XZCO5rU1uUgzjHqfO0L3uomKUzj2t9gkggQXnLaKRtUmGDPEOsBWgeztLs08Jk3xiX6j8rrCP3ibl

CxDNB4tUvjkSGqGGhcTz9zZql9V9vOHeX5lOZsI_HBmV-HewqLy8fLZ4_99RhfNEE8req4TSs8aX1-0bbAPATcEi9j5uMdRYL4QKBrDLCvbJoLj4OGEn58LqITf_eSq0NGbCTtj-

Fh7ABioiDKnQiFF5193fhh6gbDGcKjMV6oXlaYJTtAjYW9OFWtp5FEEH-gGrCcMDEeqIkEwRoNvUMnWi3jYh-NfWgagqfNKFTZVeTtuMEbXotJt_D_Zvhu2cbDI4muP1Kw8Hlr8Z

D, 1XUt3FKnEiFi98FJAEoCDEc9qo1DISpi2ZEufVvlDp_jxUrVGVRZsW1xXTQ8_gTChc2SEJ1GTmDLfJMtr8OsHr_odaGVnNtsDuX6bOWZBhvLi36qk1N3ALnUeYec0uDH05aFghMb

Giải thích

Chọn B.

Phương pháp: 

Sử dụng các công thức:

RSSPOEF0RsOZz_hBTVe--6tM81C8P01Umk8No9OU6N2DyL-XIvCPz0Jucg3iO4wHcDMpJz7BPi4n_RcM66AtIaAkLvM7sW8YLsjUAzflQ3EOdgMSOC7sfjZVLnelbV99qI0Usd5XxuUZIZfdhw

QeRNQjczU25VaoJiv3XaK5wU7wMB2JQkKQlzM0-HYvY-iHu8_ZB1tK1XU11ipgv4nSII_13ho33sSxs3gLVpRiqTfqXjYe32l9wYr3EU33CFXvkwDLWTle1y-jSfXo9aIQMYur7UvVxGkUiMeQ 

S0rmW2YsbGy5Ov3Qr8OJozcCmke3Dm0QBDIWyqqYd7HDLgYvzYpo5yhy-GNZ4EA9v843PeCTpotKecIR5vw-R9LJfxsRZiTjuNqxQKy9ozV3ea-dZenvyRlGxH6JxZwVlp-JOZcOCuqklFii9A

aC22W5z95jYtTXgP9jrltvX7OukptMwedhWSIqn_-ZpmobcibbKHybaC9WSKr6QgwdIbSQq27Aa_eBTsyfh7WIjpphNYWVwU6l4Av3JlpzxRYgIrtYimGfTSg5JdCZpq-Tn9wO-mOfZwlY_Qdw 

Cách giải:

Ta có:

qTa1np1ispYMbHvZHgcC7sb2fUOH1ZnTmmwxv8W-8Z6ZgU61cbGs06fdofFq24gAqLo5J78YnHYd5X0qkr9mH6wta6yiaKFOGPPdtpgBSbnR9vIeMg5O7PBP-sXxEZDLHO05YOEWuZJUfi7OJg 

yDdQyQNoLzdeUfbLgpns-T8-n_93xq9rlhbrtvZsg5O4mrPamWjImHXKjL7TNVZpSZ88nXARlK8E9RVUhxleoaBPGdXlzde3yyvCOmKjQcwkxnpRW7EhXuAD7cxzCKYihJ_8d_4G6JpyEUeoDg