Simplify or Evaluate a Logarithmic Expression

The question asks the student to compute the numerical value of an expression composed of logarithms (and possibly exponentials) using laws of logarithms such as product, quotient, power, and change-of-base rules.

csat-suneung 2026 Q6 3 marks View
Two real numbers $a , b$ greater than 1 satisfy $$\log _ { a } b = 3 , \quad \log _ { 3 } \frac { b } { a } = \frac { 1 } { 2 }$$ What is the value of $\log _ { 9 } a b$? [3 points]
(1) $\frac { 3 } { 8 }$
(2) $\frac { 1 } { 2 }$
(3) $\frac { 5 } { 8 }$
(4) $\frac { 3 } { 4 }$
(5) $\frac { 7 } { 8 }$
gaokao 2015 Q12 View
12. The value of $\lg 0.01 + \log _ { 2 } 16$ is \_\_\_\_.
gaokao 2015 Q9 View
9. Calculate: $\log _ { 2 } \frac { \sqrt { 2 } } { 2 } =$ $\_\_\_\_$ , $2 ^ { \log _ { 2 } 3 + \log _ { 4 } 3 } =$ $\_\_\_\_$.
gaokao 2015 Q12 View
12. If $a = \log _ { 2 } 3$ , then $2 ^ { a } + 2 ^ { - a } =$ $\_\_\_\_$ .
isi-entrance 2018 Q18 View
Let $p ( n )$ be the number of digits when $8 ^ { n }$ is written in base 6, and let $q ( n )$ be the number of digits when $6 ^ { n }$ is written in base 4. For example, $8 ^ { 2 }$ in base 6 is 144, hence $p ( 2 ) = 3$. Then $\lim _ { n \rightarrow \infty } \frac { p ( n ) q ( n ) } { n ^ { 2 } }$ equals:
(A) 1
(B) $\frac { 4 } { 3 }$
(C) $\frac { 3 } { 2 }$
(D) 2.
jee-advanced 2018 Q7 View
The value of $$\left( \left( \log _ { 2 } 9 \right) ^ { 2 } \right) ^ { \frac { 1 } { \log _ { 2 } \left( \log _ { 2 } 9 \right) } } \times ( \sqrt { 7 } ) ^ { \frac { 1 } { \log _ { 4 } 7 } }$$ is $\_\_\_\_$.
jee-main 2025 Q25 View
Let $f ( x ) = \lim _ { \mathrm { n } \rightarrow \infty } \sum _ { \mathrm { r } = 0 } ^ { \mathrm { n } } \left( \frac { \tan \left( x / 2 ^ { r + 1 } \right) + \tan ^ { 3 } \left( x / 2 ^ { r + 1 } \right) } { 1 - \tan ^ { 2 } \left( x / 2 ^ { r + 1 } \right) } \right)$. Then $\lim _ { x \rightarrow 0 } \frac { \mathrm { e } ^ { x } - \mathrm { e } ^ { f ( x ) } } { ( x - f ( x ) ) }$ is equal to
jee-main 2025 Q23 View
If $\lim _ { \mathrm { t } \rightarrow 0 } \left( \int _ { 0 } ^ { 1 } ( 3 x + 5 ) ^ { \mathrm { t } } \mathrm { d } x \right) ^ { \frac { 1 } { t } } = \frac { \alpha } { 5 \mathrm { e } } \left( \frac { 8 } { 5 } \right) ^ { \frac { 2 } { 3 } }$, then $\alpha$ is equal to $\_\_\_\_$
taiwan-gsat 2022 Q1 6 marks View
Let $a_1, a_2, a_3, a_4$ be a geometric sequence with first term 10 and common ratio 10. Let $b = \sum_{n=1}^{3} \log_{a_n} a_{n+1}$. Select the correct option.
(1) $2 < b \leq 3$
(2) $3 < b \leq 4$
(3) $4 < b \leq 5$
(4) $5 < b \leq 6$
(5) $6 < b \leq 7$
taiwan-gsat 2022 Q4 5 marks View
On a coordinate plane, it is known that vector $\overrightarrow{PQ} = \left(\log \frac{1}{5}, -10^{-5}\right)$, where point $P$ has coordinates $\left(\log \frac{1}{2}, 2^{-5}\right)$. Select the correct option.
(1) Point $Q$ is in the first quadrant
(2) Point $Q$ is in the second quadrant
(3) Point $Q$ is in the third quadrant
(4) Point $Q$ is in the fourth quadrant
(5) Point $Q$ is on a coordinate axis
taiwan-gsat 2025 Q6 5 marks View
Select the value of $\sum _ { k = 1 } ^ { 5 } \log _ { 7 } \left( \frac { 2 k - 1 } { 2 k + 1 } \right)$.
(1) $- \log 11$
(2) $\log 11$
(3) $\log \frac { 11 } { 7 }$
(4) $- \frac { \log 11 } { \log 7 }$
(5) $\frac { \log 11 } { \log 7 }$
turkey-yks 2010 Q27 View
$$\frac{1}{\log_{2} 6} + \frac{1}{\log_{3} 6}$$
Which of the following is this expression equal to?
A) $\frac{1}{3}$
B) $1$
C) $2$
D) $\log_{6} 2$
E) $\log_{6} 3$
turkey-yks 2010 Q29 View
For positive real numbers $a$, $b$, $c$ different from 1, $$\log_{a} b = \frac{1}{2}, \quad \log_{a} c = 3$$ Given this, what is the value of the expression $\log_{b}\left(\frac{b^{2}}{c\sqrt{a}}\right)$?
A) $\frac{3}{2}$
B) $\frac{5}{2}$
C) $\frac{5}{3}$
D) $-6$
E) $-5$
turkey-yks 2011 Q5 View
$12^{a} = 2$
$$6^{b} = 3$$
Given that, what is the value of the expression $\mathbf{12}^{\boldsymbol{(}\mathbf{1} - \mathbf{a}\mathbf{)2b}}$?
A) 15 B) 16 C) 9 D) 8 E) 4
turkey-yks 2012 Q4 View
Let $\mathbf { x }$ and $\mathbf { y }$ be real numbers.
$$2 ^ { x } - 2 ^ { -y } \left( 2 ^ { x+y } - 2 \right)$$
Which of the following is this expression equal to?
A) $2 ^ { x+1 }$
B) $2 ^ { y-x }$
C) $2 ^ { -y+1 }$
D) $\frac { 2 } { 9 }$
E) $\frac { 4 } { 9 }$
turkey-yks 2016 Q31 View
$$\log _ { 2 } \sqrt { 8 \sqrt { 4 \sqrt { 2 } } }$$
What is the result of this operation?
A) $\frac { 13 } { 8 }$
B) $\frac { 15 } { 8 }$
C) $\frac { 17 } { 8 }$
D) $\frac { 23 } { 16 }$
E) $\frac { 27 } { 16 }$
turkey-yks 2017 Q33 View
$\frac { \log _ { 3 } \sqrt { 27 } + \log _ { 27 } \sqrt { 3 } } { \log _ { 3 } \sqrt { 27 } - \log _ { 27 } \sqrt { 3 } }$\ What is the result of this operation?\ A) $\frac { 3 } { 2 }$\ B) $\frac { 4 } { 3 }$\ C) $\frac { 5 } { 4 }$\ D) $\frac { 6 } { 5 }$\ E) $\frac { 7 } { 6 }$
turkey-yks 2018 Q10 View
On a ruler-like scale with integers from 1 to 50 written on it, the distance of each integer $n$ from 1 is $\log n$ units.
When two identical rulers with this property are placed one below the other as shown in the figure, the number 42 on the upper ruler aligns with the number 28 on the lower ruler, and the number 33 on the upper ruler aligns with the number $x$ on the lower ruler.
Accordingly, what is $x$?
A) 18 B) 19 C) 20 D) 21 E) 22
turkey-yks 2019 Q15 View
Ada calculates the value of $\log _ { 2 } n$ on her scientific calculator for every positive integer n where $\mathrm { n } \leq 32$, and observes that each value is either an integer or a decimal number. Ada writes down either the number itself if the value displayed on the screen is an integer, or the integer part of the number if it is a decimal, and then finds the sum of these numbers she wrote down. Accordingly, what is the result of the sum that Ada found?
A) 94
B) 97
C) 100
D) 103
E) 106
turkey-yks 2021 Q13 View
On a calculator, when an operation is performed, the machine displays the result as a whole number if the result is an integer, or displays the integer part along with the first two decimal places after the decimal point if the result is a decimal number.
When Nevzat performs the operation $\ln ( 9{,}6 )$ on this calculator, he sees the value 2.26 on the screen, and when he performs the operation $\ln ( 0{,}3 )$, he sees the value $-1{,}20$ on the screen.
When Nevzat performs the operation $\ln ( 0{,}5 )$ on this calculator, what value does he see on the screen?
A) $-0{,}61$
B) $-0{,}65$
C) $-0{,}69$
D) $-0{,}73$
E) $-0{,}77$