# Logarithms

 Logarithms What are logarithms? Who was 'John - the man - Napier'? Converting between log equations and index equations  Ex8.06, Ex9.01 Theta pg 34 & 35 NuLake EAS Q173 - 194 Log Rules Comparing the log rules to index manipulations Simplifying Log expressions using the three log rules Log(A) + Log(B) = Log(AB) Log(A) - Log(B) = Log(A/B) nLog(A) = Log(A)n  Ex9.02 Theta pg 36 & 37 NuLake EAS Q195 - 218 14 Index Equations Solving index equations using logs eg. 3x = 17 Activity Index equations practice (www.transum.org)  Ex9.03, Ex9.04 Theta pg 38 & 39 & 40 NuLake EAS Q219 - 233

#### Jump down to... Introduction | log & index form | Log rules | Index Equations

 Log264=6 "What is the power on 2 which gives 64? The power is 6 Common logs are Log10  (base 10) Natural Logs are Loge (base e = 2.71828...) Index form bp=q Logs 'get at' the powers Log form logb(q)=p "log of q to the base b is p" or "Log base b of q is p"

# Converting between log & index forms

 1) First example Solution 2) 2nd example Solution 3) 3rd example Solution Mouse over key words  ### Summary:    # Log Rules

## Three key log rules help to simplify & solve equations

 Multiplying algebra terms means ADD the powers. 1) When we multiply numbers we ADD the logs. Dividing algebra terms means SUBTRACT the powers. 2) When we divide numbers we Subtract the logs. A power on a power means we MULTIPLY the powers.3) When we raise a numbers by a power we MULTIPLY the log by that power. # Index Equations

 1) Take the Logs of both sides 2) Use 3rd Log rule 3) Solve Mouse over key words  ### Summary:   