First 5th year difficult topic!! How can I do manipulation of formulae?

naxmax9

My teacher says they aren't important but I DON'T beileve him and this looks like stuff that will be important in Applied Maths. He spent like 5 minutes on it and I have NO idea how to do it. Does anyone know a site with a tutorial for the manipulation or something because I'm lost (Higher Level Maths)

Dave0301

What is it you are looking to manipulate? I might be able to give you some pointers.

Also, notes for Applied Maths can be found here.

naxmax9

Dave0301 wrote: »

What is it you are looking to manipulate? I might be able to give you some pointers.

Also, notes for Applied Maths can be found here.

I can't do the questions in my book. Now he didn't assign us maths homework and we are moving on because he doesn't think they are important but I spent my whole Sunday trying to learn them anyways.

I have no idea how to manipulate v= u + at by finding t in terms of v,u and a or v2 = u2 + 2as by finding u in terms of v a and s

Dave0301

naxmax9 wrote: »

I have no idea how to manipulate v= u + at by finding t in terms of v,u and a or v2 = u2 + 2as by finding u in terms of v a and s

To get t in terms of v, u and a:

v = u + at (subtract u from both sides)

v - u = at (divide both sides by a)

(v - u)/a = t

To get u in terms of v a and s:

v^2 = u^2 + 2as (subtract 2as from both sides)

v^2 - 2as = u^2 (square root both sides)

(V^2 - 2as)^0.5 = u

The to the power of 0.5 is square root of what is in the bracket. Sorry for the format, but best I can do on short notice.

naxmax9

Dave0301 wrote: »

To get t in terms of v, u and a:

v = u + at (subtract u from both sides)

v - u = at (divide both sides by a)

(v - u)/a = t

To get u in terms of v a and s:

v^2 = u^2 + 2as (subtract 2as from both sides)

v^2 - 2as = u^2 (square root both sides)

(V^2 - 2as)^0.5 = u

The to the power of 0.5 is square root of what is in the bracket. Sorry for the format, but best I can do on short notice.

I can already see the pattern. Thanks for this. I'm going to analyse all of this to the best of my ability. Thank you so much!

evolving_doors

naxmax9 wrote: »

I can't do the questions in my book. Now he didn't assign us maths homework and we are moving on because he doesn't think they are important but I spent my whole Sunday trying to learn them anyways.

I have no idea how to manipulate v= u + at by finding t in terms of v,u and a or v2 = u2 + 2as by finding u in terms of v a and s

Being optimistic, I suspect that it'll be covered within other areas of the course.

Perhaps you might recall in the Junior Cert rewriting an equation of a line into the form y=mx + c (to get your slope m)

So lets say you had a line 2x + 3y = 8 and you need to 'manipulate' it so that everything is pushed over to the right hand side and you are left with y on the left: Here's the steps
2x + 3y = 8
3y = 8 - 2x (swop side change the sign)
3y = -2x + 8 (re arrange so the x part is first)
y=(-2/3)x + 8/3 (Divide across by 3 to get rid of the 3 in front of the y)
Now you've manipulated it to get y on it's own, it's in the form y=mx+C and you can see the part in front of the x is -2/3 which is m.. the slope.

Another popular one is converting Centigrade to Farenheit
F=1.8C + 32
if you manipulate it, it should come out as C= F/1.8 - 32/1.8

Also you might have done this a little with simultaneous equations so you can cancel
(eq1) y = 2X + 20
(eq2) 5x+ 8y = 50

so with a little bit of manipulation you want to have the 2 equations looking the same to commence solving simultaneous equations.

(eq1) 2X - y = -20
(eq2) 5x+ 8y = 50

Does that ring a bell?

The hardest it will get would be when you've fractions over fractions, some squares or square roots thrown in.... and Logs ... and Trigonometry .... actually I can see why your teacher might be thinking about coming back to it under certain topics rather than dealing with it as a discrete skill on it's own. You'd still need to be handy with it though.

There's umpteen videos on youtube e.g. https://www.youtube.com/watch?v=MTahM8_5bG8



Your original question "v= u + at by finding t in terms of v,u and a "
Just think of it as 't Pushed over to be ON IT'S OWN on the Left Hand Side with a bunch of other variables on the RHS' i.e. with v's u's and a's in it'.

You can post questions in the Maths forums also, they aren't allowed to work it all out for you, but just give you hints if you're stuck.

vestedinterest

https://youtu.be/fDgTW_QZuGE

Video on changing the subject of a formula.

rovertom

naxmax9 wrote: »

My teacher says they aren't important but I DON'T beileve him and this looks like stuff that will be important in Applied Maths. He spent like 5 minutes on it and I have NO idea how to do it. Does anyone know a site with a tutorial for the manipulation or something because I'm lost (Higher Level Maths)

Did you do higher junior maths