Laws of Logarithms 5.6. Laws of Logarithms O If M and N are positive real numbers and b is a...

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Laws of Logarithms 5.6

Transcript of Laws of Logarithms 5.6. Laws of Logarithms O If M and N are positive real numbers and b is a...

Page 1: Laws of Logarithms 5.6. Laws of Logarithms O If M and N are positive real numbers and b is a positive number such that b  1, then O 1. log b MN = log.

Laws of Logarithms

5.6

Page 2: Laws of Logarithms 5.6. Laws of Logarithms O If M and N are positive real numbers and b is a positive number such that b  1, then O 1. log b MN = log.

Laws of LogarithmsO If M and N are positive real numbers and

b is a positive number such that b 1, then

O 1. logb MN = logb M + logb N

O 2. logb = logb M - logb N

O 3. logb M = logb N if and only if M = N

O 4. logb Mk = k logb M, for any real number k.

Page 3: Laws of Logarithms 5.6. Laws of Logarithms O If M and N are positive real numbers and b is a positive number such that b  1, then O 1. log b MN = log.

Laws of Logarithms

O 5.

O 6.

O 7.

O 8. *ln has the same laws.

Page 4: Laws of Logarithms 5.6. Laws of Logarithms O If M and N are positive real numbers and b is a positive number such that b  1, then O 1. log b MN = log.

Ex. Write each expression in terms of Log M and log N.

O A) log

O B)

O C) log M2

Page 5: Laws of Logarithms 5.6. Laws of Logarithms O If M and N are positive real numbers and b is a positive number such that b  1, then O 1. log b MN = log.

Ex. Write each expression as a rational number or as a single logarithm.

O A) ln 2 + ln 6 – ln 9

O B) log 6 9 + log 6 5

O C) log 3 – log 6 – log 5

O D) (2log b M – log b N – log b P)

Page 6: Laws of Logarithms 5.6. Laws of Logarithms O If M and N are positive real numbers and b is a positive number such that b  1, then O 1. log b MN = log.

Ex. Simplify each expression with out a calculator.

O A) ln e2

B) ln

O C) ln e3x + 5

D) 102 log

6

O E) 103 + log 4

F) e1 + 2 ln

x

Page 7: Laws of Logarithms 5.6. Laws of Logarithms O If M and N are positive real numbers and b is a positive number such that b  1, then O 1. log b MN = log.

Ex. Solve the given equation.

OA) log 2 (x + 2) + log 2 5 = 4

OB) log 4 (2x + 1) – log 4 (x – 2) = 1

Page 8: Laws of Logarithms 5.6. Laws of Logarithms O If M and N are positive real numbers and b is a positive number such that b  1, then O 1. log b MN = log.

Ex. Express y in terms of x

O

O Ex. 6 Given log 4 3 = x & log 4 7 =y, write the following in terms of x and y:O log 4 63