The point here, sally1, is that we don't need a calculator for ANY of them....!!! We're just using some log properties to evaluate them.....here's the second one....
2) log5 0.2 ..... this one looks tricky, but let's remember something...that 0.2 = 2/10 = 1/5
And we can write 1/5 as 5-1 (remember that ??)
So we have.......
log5 5-1 and by a log property, we can bring the -1 out front ..... and we have.....
(-1)log5 5 ....and log5 5 = 1 ...so we have....
(-1)(1) = -1
3) These used to give me trouble...once you see the 'trick,' it's easy......let me give you an example...let's say we have
2 log2 4
Note that log2 4 just asks..what power do we need to raise 2 to to get 4??? The answer is 2
So we really have
22 = 4 Note that this was just the last number in the original exponent!!!
In general when we have .....a loga b the answer is just "b".....this is one you may have to think about a little bit!!!
So.....in your problem 5 log5 19 ...the answer is just "19"
4) e ln √11 Note that there is a little "e" implied here we can write this as
e lne √11 And we have the same situation as the previous problem!!!
The answer is just "√11"
Lastly
5) ln (1/e) = ln (e) -1 and by a property of exponents we can bring the -1 to the front
So we have
(-1) ln e and ... ln e = 1 ... so we have
(-1)(1) = -1
And that's it!!!
1) Note that √9 = 9 1/2 ....so we have...
Log 9 9 1/2 .... and by a property of logs, we can bring the 1/2 in front of the expression..so...
1/2 Log 9 9 .....and Log 9 9 = 1 ....so we have
1/2 * 1 = 1/2
For the log problems I'm trying to put it into the calculator but the answers are not coming out right.
That's probably because you're trying to use base 10......most of these (like the first one, for instance) are using a different base.
The point here, sally1, is that we don't need a calculator for ANY of them....!!! We're just using some log properties to evaluate them.....here's the second one....
2) log5 0.2 ..... this one looks tricky, but let's remember something...that 0.2 = 2/10 = 1/5
And we can write 1/5 as 5-1 (remember that ??)
So we have.......
log5 5-1 and by a log property, we can bring the -1 out front ..... and we have.....
(-1)log5 5 ....and log5 5 = 1 ...so we have....
(-1)(1) = -1
3) These used to give me trouble...once you see the 'trick,' it's easy......let me give you an example...let's say we have
2 log2 4
Note that log2 4 just asks..what power do we need to raise 2 to to get 4??? The answer is 2
So we really have
22 = 4 Note that this was just the last number in the original exponent!!!
In general when we have .....a loga b the answer is just "b".....this is one you may have to think about a little bit!!!
So.....in your problem 5 log5 19 ...the answer is just "19"
4) e ln √11 Note that there is a little "e" implied here we can write this as
e lne √11 And we have the same situation as the previous problem!!!
The answer is just "√11"
Lastly
5) ln (1/e) = ln (e) -1 and by a property of exponents we can bring the -1 to the front
So we have
(-1) ln e and ... ln e = 1 ... so we have
(-1)(1) = -1
And that's it!!!