You are Here: Home >< Maths

# A few quick questions, Plz help watch

1. ok just a few things i need help with.

integration, denote to c

3x^-1= 3in(x) + c or in(3x) + c ??

x^-2= i can do this if it is x^-1 and x^-3, etc. just not 2, unless its 1/1x^-1 which surely cant be right?

3/2 exp (3x) = how do you integrate if its a fraction? as in 3 over 2?

erm check if i done this rght: 3 S (x^3 + x^2 +x) = 3 1/4x^4 + 1/3x^3 + x^2/2 + c ?? im worried about how you place the 3 into the answer have i done it right or do you need to do something else.

Also could someone work through this example: that way i know how to use the quotient rule for differentiation!!

x^2 + 2x + 4
___________
x+2

will appreciate the help people!!
2. Well, 3x^-1 means 3 . (x^-1), so it integrates to 3 ln x + c.

The integral of x^-2 is (x^-1)/-1 = -x^-1 = -1/x.

3/2 is just a constant. Treat it like you'd treat, say, the 4 in: 4 exp 3x.

Your next integral - there should be a bracket round everything, so 3 (1/4x^4 + 1/3x^3 + x^2/2) + c. (Another acceptable answer would be 3 (1/4x^4 + 1/3x^3 + x^2/2 + c) - the 'c' is different in both cases, but that doesn't make any difference.)

Quotient rule... .

And so

which you can then simplify.

Phew, long post, hope I didn't make any slips.

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: August 27, 2007
Today on TSR

### University open days

• Southampton Solent University
Sun, 18 Nov '18
Wed, 21 Nov '18
• Buckinghamshire New University
Wed, 21 Nov '18
Poll
Useful resources

### 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