x Turn on thread page Beta
 You are Here: Home >< Maths

# Log rule watch

1. Ok I get logs , but there is just one rule i dont get:

How does ?

I get that if you log the LHS to get

then take the top log down and it becomes a sum of the 2 logs. Then so i'm left with just but how does that = x?
2. (Original post by Carlo08)
Ok I get logs , but there is just one rule i dont get:

How does:

I get that if you log the LHS to get

then take the top log down and it becomes a sum of the 2 logs. Then so i'm left with just but how does that = x?

From the basic definition of logs:

Take the left hand side, put each side to the power of a to get:

From the right hand side of the first line, we know that the right hand side here is equal to x. This gives:

Turn on thread page Beta
TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: January 28, 2010
Today on TSR

### Four things top students are doing

Over the Easter break

Poll
Useful resources

## Make your revision easier

### Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

### How to use LaTex

Writing equations the easy way

### Study habits of A* students

Top tips from students who have already aced their exams

Can you help? Study help unanswered threads

## Groups associated with this forum:

View associated groups

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE