Secondary 3 A Maths Logarim

Secondary 3 A Maths

Chapter 2.  Logarim

1)Changing indices to log

a^x= b

x  = log_ab

Example

10³=1000

3=log₁₀1000

3^x=2

x=log₃ 2

Qns)

Q1)3^x=4

Q2)2^y=2

2)Changing log to indices

log_ab = y

b       =  a^y

example

log₃ x = 2

x        = 3²

x        = 9

Q1) log₄y = 3

Q2) log₂x =2

3) Changing Of Base

	Log b
Logab =	-------
	Log a

	Log 5
Log45 =	-------
	Log 4

Q1) find log₆7

Q2) find log₈9

 <Logarithm/> tags

4) Power law of log

alog b = log b^a

2log 3 = log 3²

Take note

(Log b)²  = (log b)(logb)

                not equal to log b² 

5) Addition law of log

Log (ab) = Log a + logb

Log (12) = Log 3 + log4

Log (3x) = log 3 + logx

6) Subtraction law of log

log (a/b) = log a – log b

log (x/8)  = log x-  log 8

Qn1) Log(4x)

Qn2) log (7/x)