AS Integration-easy question----i'm still stuck!

Please could someone help me out here:

A curve is such that, dy/dx= 12/x*3(cubed)-2 (sorry guys, Idk how to do the fraction symbol)
Given that the curve passes the point (1,5), find the equation of the curve.

Thanks a lot

Reply 1

Indolence

Original post by wallflower#1

...

You'll have to integrate the expression, so that you have an expression with an arbitrary constant. Then, given the points provided,

(x_1, y_1)

you let the expression equal

y_1

and you plug in

x_1

, to ascertain the arbitrary constant.

Reply 2

wallflower#1

OP

Umm..I'm still new to the topic...so how do we integrate?? :s-smilie:

Reply 3

Indolence

Original post by wallflower#1

...

In this case, it'd probably be more beneficial for you to look over integration first—ExamSolutions would be of use.

Reply 4

wallflower#1

OP

okay, thanks anyways

Original post by wallflower#1

Umm..I'm still new to the topic...so how do we integrate?? :s-smilie:

If you want to integrate

ax^n

with respect to

x

and

n \neq -1

you end up with

\displaystyle \frac{ax^{n+1}}{n+1} + k

where k is a constant. If you differentiate the answer you should see why the constant is necessary.

Some people remember this by saying things like:

Add one to the power and divide by the new power

or the yucky but memorable

Add one more and drop it through the trapdoor

Reply 6

wallflower#1

OP

Original post by Mr M

If you want to integrate

ax^n

with respect to

x

and

n \neq -1

you end up with

\displaystyle \frac{ax^{n+1}}{n+1} + k

where k is a constant. If you differentiate the answer you should see why the constant is necessary.

Some people remember this by saying things like:

Add one to the power and divide by the new power

or the yucky but memorable

Add one more and drop it through the trapdoor

Ohhh...I think I'm starting to remember what we're supposed to do....okie...thanks for the help