HELP! (1 Viewer)

[Beaconite]

okay e.g

we have to integrate dv/100 - v^2

we use partial fractions to solve it.

But can we use this to solve it : 1/2a ln (a+v/a-v), where a=10 << this comes from partial fractions

so instead of using partial fractions, can we use ^^ form straight away?

 

[Beaconite]

Looks fine, you end up with the same answer:

You get the same answer, but what I am asking is can we use the form : 1/2a ln (a-v/a+v) straight away in the exam instead of using partial fractions (finding a and b and integrating)

 

[Aysce]

You get the same answer, but what I am asking is can we use the form : 1/2a ln (a-v/a+v) straight away in the exam instead of using partial fractions (finding a and b and integrating)

I don't think you are able to do this - it is recommended you do it from scratch rather than just applying a formula.

 

[Beaconite]

I don't think you are able to do this - it is recommended you do it from scratch rather than just applying a formula.

Will they take away marks if I use the formula?

 

[Aysce]

Will they take away marks if I use the formula?

Possibly, but I'm not entirely sure. Best to just do it from scratch - ask Carrotsticks, he'd know.

 

[Beaconite]

Possibly, but I'm not entirely sure. Best to just do it from scratch - ask Carrotsticks, he'd know.

aright , thanks m8

 

[Carrotsticks]

Will they take away marks if I use the formula?

Yep. Skip at MOST the Partial Fraction step (the whole A-B, A+B thing and simultaneous equations). Do everything else, showing steps.

 

[Beaconite]

If it is part of a question then I believe you can use it. If the question is like a 3 mark question 1 partial fractions integral then no.

for mechanics questions, do I have to use partial fractions from scratch? or just use the formula straight away?

 

[Carrotsticks]

for mechanics questions, do I have to use partial fractions from scratch? or just use the formula straight away?

I suppose you can use the formula, though you'll cop it pretty hard if you made an error using that formula (ie: no working out for any marks)

 

[Beaconite]

I suppose you can use the formula, though you'll cop it pretty hard if you made an error using that formula (ie: no working out for any marks)

Yep okay, thanks Carrot