Calculus/Math

Advertisement


Question
3 ln (x + 7) - 4 ln (x^2 + 7)

Answer
When 4•ln(3) is seen, it is the same as ln(3^4).
This said, 3•ln(x+7) is the same as ln((x+7)^3).
Also, -4ln(x²+7) is the same as ln((x+7)^-4) = ln(1/(x+7)^4).

Now the equation can be rewritten as ln((x+7)^3) - ln(1/(x+7)^4).

Now when you have -ln(1/a), it is the same as ln(a).
In this way,  - ln(1/(x+7)^4) is the same as  + ln((x+7)^4).

Now we have ln((x+7)^3) + ln((x+7)^4).

It is also known that ln(a)•ln(b) = ln(ab), so we can say that
ln((x+7)^3) + ln((x+7)^4) = ln((x+7)^3•(x+7)^4).

Calculus

All Answers


Answers by Expert:


Ask Experts

Volunteer


Scotto

Expertise

Any kind of calculus question you want. I also have answered some questions in Physics (mass, momentum, falling bodies), Chemistry (charge, reactions, symbols, molecules), and Biology.

Experience

Experience in the area: I have tutored students in all areas of mathematics for over 25 years. Education/Credentials: BSand MS in Mathematics from Oregon State University, where I completed sophomore course in Physics and Chemistry. I received both degrees with high honors. Awards and Honors: I have passed Actuarial tests 100, 110, and 135.

Publications
Maybe not a publication, but I have respond to well oveer 7,500 questions on the PC. Well over 2,000 of them have been in calculus.

Education/Credentials
I aquired well over 40 hours of upper division courses. This was well over the number that were required. I graduated with honors in both my BS and MS degree from Oregon State University. I was allowed to jump into a few junior level courses my sophomore year.

Awards and Honors
I have been nominated as the expert of the month several times. All of my scores right now are at least a 9.8 average (out of 10).

Past/Present Clients
My past clients have been students at OSU, students at the college in South Seattle, referals from a company, friends and aquantenances, people from my church, and people like you from all over the world.

©2012 About.com, a part of The New York Times Company. All rights reserved.