Which of the following inequalities are NOT correct? (A) If $a >1,b> 1$, then $\log_ba+ \log_a b ≤2$ Choose the correct answer from the options given below: |
(A), (B) and (D) only (A), (B) and (C) only (C) and (D) only (B), (C) and (D) only |
(A), (B) and (C) only |
The correct answer is Option (2) → (A), (B) and (C) only • (A) is false in general because $\frac{\ln a}{\ln b}+\frac{\ln b}{\ln a}\ge 2$, not $\le 2$. • (B) is false because the minimum of $9^{x}+9^{1-x}$ is $6$, which is not $\ge 9$. • (C) is false because $\frac{a}{b}+\frac{b}{c}+\frac{c}{a}\ge 3$, not $\le 3$. • (D) is true for three distinct real numbers (with positive values): $(a+b)(b+c)(c+a)>8abc$. Thus, the NOT correct statements are (A), (B), and (C). |