SOLUTION: how to expand ln x^3(x-2)^2/ sqrt x^2+5

Algebra ->  Logarithm Solvers, Trainers and Word Problems -> SOLUTION: how to expand ln x^3(x-2)^2/ sqrt x^2+5      Log On


   



Question 883007: how to expand ln x^3(x-2)^2/ sqrt x^2+5
Answer by Leaf W.(135) About Me  (Show Source):
You can put this solution on YOUR website!
Hello!
***
You can use a few "logarithm rules" to expand out logarithms of any base:
1. The log of the product of two numbers is the same as adding the individual logs of each number: log+%28a%2C+%28bc%29%29+=+log+%28a%2C+b%29+%2B+log+%28a%2C+c%29
2. The log of the quotient of two numbers is the same as subtracting the individual logs of each number: log%28a%2C%28b%2Fc%29%29+=+log%28a%2Cb%29+-+log%28a%2Cc%29
3. The log of a number raised to a certain exponent is the same as the value of that exponent multiplied by the log of that number: log%28a%2C%28b%5Ec%29%29+=+c%2Alog%28a%2Cb%29
***
Now let us apply those rules to this case!
ln%28%28x%5E3+%2A+%28x+-+2%29%5E2%29%2F%28sqrt%28x%5E2%2B5%29%29%29
Use rule #2 to get rid of the division: ln%28x%5E3+%2A+%28x-2%29%5E2%29+-+ln%28sqrt%28x%5E2+%2B+5%29%29
Use rule #1 to get rid of the multiplication: ln%28x%5E3%29+%2B+ln%28%28x-2%29%5E2%29+-+ln%28sqrt%28x%5E2+%2B+5%29%29
Since taking the square root is the same thing as raising to the one-half power: ln%28x%5E3%29+%2B+ln%28%28x+-+2%29%5E2%29+-+ln%28%28x%5E2+%2B+5%29%5E%281%2F2%29%29
Use rule #3 to get rid of exponents: 3ln%28x%29+%2B+2ln%28x+-+2%29+-+%281%2F2%29ln%28x%5E2+%2B+5%29
***
Therefore, the expanded expression is 3ln%28x%29+%2B+2ln%28x+-+2%29+-+%281%2F2%29ln%28x%5E2+%2B+5%29
I hope this helps! =)