# calculus

posted by on .

-3ln l-2xl/5+2x
-3ln abs -2x over 5+2x

• calculus - ,

So what do you need? the derivative?

• calculus - ,

find the derivative of the function y

I've completed several of these and keep coming up with the wrong answer...if you can complete it, and have time, please show as much as you can, so I can see what I am doing wrong. Thanks for the reply.

• calculus - ,

-3ln l-2xl/5+2x
-3ln abs -2x over 5+2x
=====================
If I assume the derivative is desired and we are talking about:
-3 ln | -2x |
-------------
(5 + 2 x)

there is no such thing as ln of a negative number, so the only effect of the absolute value is to make this work for negative as well as positive x. Do the problem for 2x

bottom*derivative of top - top*derivative of bottom
---------------------------
bottom squared

(5+2x)(-3*2/2x) + 3 ln 2x * 2
-------------------------------
25 +20 x + 4 x^2

-15/x - 6 + 6 ln 2x
--------------------
25+20x + 4 x^2

-15 - 6x + 6 x ln 2x
--------------------
25 x + 20 x^2 + 4 x^3

• calculus - ,

Oh, and call x the absolute value |x| because we are doing this for the absolute value of x

• calculus - ,

Thanks Damon....that problem was wrong also...it should have been a negative absolute. that has been my problem all along....I wanted to be sure that my formula and math was correct....and you confirmed that for me. Thanks...I guess I will have to settle for a 90...cause I have a whole nother chapter to complete by April 30th.