For AI agents: use /llms.txt for the Nakafa content index.
Like exponents, logarithms also have several important properties that need to be understood. These properties will be very helpful in solving various logarithmic problems.
Let a > 0 a > 0 a > 0 and a ≠ 1 a \neq 1 a = 1 , , , , , where are real numbers . The following are :
a , b , c , m , n a, b, c, m, n a , b , c , m , n ( a , b , c , m , n ∈ R ) (a, b, c, m, n \in \mathbb{R}) ( a , b , c , m , n ∈ R ) logarithm properties
a log a = 1 ^a\log a = 1 a log a = 1
a log 1 = 0 ^a\log 1 = 0 a log 1 = 0
a log a n = n ^a\log a^n = n a log a n = n
a log ( b × c ) = a log b + a log c ^a\log (b \times c) = ^a\log b + ^a\log c a log ( b × c ) = a log b + a log c
a log ( b c ) = a log b − a log c ^a\log \left(\frac{b}{c}\right) = ^a\log b - ^a\log c a log ( c b ) = a log b − a log c
a log b n = n ⋅ a log b ^a\log b^n = n \cdot ^a\log b a log b n = n ⋅ a log b
a log b = m log b m log a = 1 b log a ^a\log b = \frac{^m\log b}{^m\log a} = \frac{1}{^b\log a} a log b = m l o g a m l o g b = b l o g a 1
a log b × b log c = a log c ^a\log b \times ^b\log c = ^a\log c a log b × b log c = a log c
Property 4 4 4 : a log ( b × c ) = a log b + a log c ^a\log (b \times c) = ^a\log b + ^a\log c a log ( b × c ) = a log b + a log c
Proof: Let a log b = m ^a\log b = m a log b = m and a log c = n ^a\log c = n a log c = n
b = a m b = a^m b = a m and c = a n c = a^n c = a n
Using the property of exponents:
Property 5 5 5 : a log ( b c ) = a log b − a log c ^a\log \left(\frac{b}{c}\right) = ^a\log b - ^a\log c a log ( c b ) = a log b − a log c
Proof: Let a log b = m ^a\log b = m a log b = m and a log c = n ^a\log c = n a log c = n
Then b = a m b = a^m b = a m and c = a n c = a^n c = a n
Recall that a m a n = a m − n \frac{a^m}{a^n} = a^{m-n} a n a m = a m − n , so:
Property 6 6 6 : a log b n = n ⋅ a log b ^a\log b^n = n \cdot ^a\log b a log b n = n ⋅ a log b
Proof: Let a log b = m ^a\log b = m a log b = m
a log b n ^a\log b^n a log b n means the logarithm of b b b raised
to the power of n n n
a log b n = a log ( b × b × b × … × b ⏟ n factors ) ^a\log b^n = ^a\log (\underbrace{b \times b \times b \times \ldots \times b}_{n \text{ factors}}) a log b n = a log ( n factors b × b × b × … × b ) Using property 4 4 4 repeatedly:
Property 7 7 7 : a log b = m log b m log a = 1 b log a ^a\log b = \frac{^m\log b}{^m\log a} = \frac{1}{^b\log a} a log b = m l o g a m l o g b = b l o g a 1
Proof:
Based on the definition of logarithm, a log b = c ^a\log b = c a log b = c if and only if b = a c b = a^c b = a c
Suppose we use base m m m for the logarithm of b b b :
Since c = a log b c = ^a\log b c = a log b , then:
Property 8 8 8 : a log b × b log c = a log c ^a\log b \times ^b\log c = ^a\log c a log b × b log c = a log c
Proof:
Based on the definition:
Substitute the value of b b b into the equation for c c c :
Since c = a m n c = a^{mn} c = a mn , then:
Suppose we want to calculate 5 log 125 ^5\log 125 5 log 125 .
Simplify the following expressions:
9 log 81 ^9\log 81 9 log 81
2 log 64 − 2 log 16 ^2\log 64 - ^2\log 16 2 log 64 − 2 log 16
4 log 16 10 ^4\log 16^{10} 4 log 1 6 10
If 5 log 4 = m ^5\log 4 = m 5 log 4 = m , 4 log 3 = n ^4\log 3 = n 4 log 3 = n , express 12 log 100 ^{12}\log 100 12 log 100 in terms of and .
The population of city A A A in 2010 2010 2010 was 300,000 people 300{,}000 \text{ people} 300 , 000 people . The average population growth rate is 6 % 6\% 6% per year. If the population growth is assumed to be the same each year, in how many years will the population of city A A A become 1 million 1 \text{ million} 1 million ?
How much time is needed for Dini's money, which was initially Rp 2,000,000.00 \text{Rp}2{,}000{,}000.00 Rp 2 , 000 , 000.00 , to become Rp 6,500,000.00 \text{Rp}6{,}500{,}000.00 Rp 6 , 500 , 000.00 if she saves it in a bank that gives her an interest rate of 12 % 12\% 12% ?
Determining logarithm values
Answer:
Answer:
Answer:
Given that 5 log 4 = m ^5\log 4 = m 5 log 4 = m , 4 log 3 = n ^4\log 3 = n 4 log 3 = n
Then:
The initial population is 300,000 people 300{,}000 \text{ people} 300 , 000 people
The annual population growth is 6 % 6\% 6% .
The appropriate function to describe population growth in x years x \text{ years} x years is:
The initial savings are Rp 2,000,000.00 \text{Rp}2{,}000{,}000.00 Rp 2 , 000 , 000.00
The final savings are Rp 6,500,000.00 \text{Rp}6{,}500{,}000.00 Rp 6 , 500 , 000.00
The interest rate is 12 % 12\% 12% .
The appropriate function to describe Dini's savings in x years x \text{ years} x years is:
For a population of 1,000,000 people 1{,}000{,}000 \text{ people} 1 , 000 , 000 people :
Therefore, the population will reach 1,000,000 people 1{,}000{,}000 \text{ people} 1 , 000 , 000 people in 20 20 20 or 21 years 21 \text{ years} 21 years .
For a final saving amount of Rp 6,500,000.00 \text{Rp}6{,}500{,}000.00 Rp 6 , 500 , 000.00 :
Therefore, Dini's savings will reach Rp 6,500,000.00 \text{Rp}6{,}500{,}000.00 Rp 6 , 500 , 000.00 in 10 years 10 \text{ years} 10 years .