Dreading ordinary level maths!!!!

Ficheall

hawaiichair wrote: »

help please?
A farmer ploughs a field with his tractor. The distance of the tractor from the gate of the field after t seconds is given by
s=3t^2 – 6t
(s is in metres)

the distance from the gate to the end of the field is 105 m – how many secs does it take the tractor to reach the end of the field?

I know it's 105=3t^2 – 6t but I can't figure it out after that

You have the 105=3t^2-6t right - now you just want to solve for t.
Rearranging we get:
3t^2-6t-105 = 0
which is the familiar quadratic form we all know and love.
Here, you can use your (-b +/- square root(b^2-4ac))/2a formula.
a=the t^2 coefficient = 3
b= the t coefficient=-6
c=the constant = -105
so
(-(-6)+/- sqrt ((-6)^2-(4)(3)(-105)))/2(3)
(6 +/- sqrt(36+1260))/6
(6 +/- 36)/6
so your two possible answers are:
7 or -5.
Obviously it cannot take -5 seconds to cross the field, so your answer is 7 seconds.

Laisurg

LilMissCiara wrote: »

No

Attempt Marks

Try EVERYTHING!

This is exactly it, getting a good grasp of part As and Bs is not very hard, then just chuck some random stuff out for part Cs if you have no clue, make sure you get the bulk of the marks in the easy questions (question 1, 4, 5 sometimes and arguably 7 in paper 1, 1,3, 7 and 9 in paper 2) some are much trickier than the others but you'll be able to get the part As and Bs, all you need is 240 marks to pass, wake up early tomorrow and study for a few hours.

randylonghorn

Ficheall wrote: »

Obviously it cannot take -5 seconds to cross the field, so your answer is 7 seconds.

Have you considered the possibility of a bull after him? >_>

More seriously, thanks Ficheall, the help is appreciated I'm sure.

guitarzero

I was in the same situation all them years back.

Step one. Stop really giving a ****, the LC is so over rated, seriously.
Step two. Go over some past papers and see what you can do.
Step three. If you think you have a chance of passing then you are grand, chill out. If you dont think you'll pass then take an hour, see what you cant understand and see if you can pick up any extra info.

Just stop caring. Where you worry your brain freezes. Go in, sit down and just say I dont give a bollox cuz its not going to change my life that much.

The Leaving Cert is just Y2K in a classroom.

Planemo

Ficheall wrote: »

You have the 105=3t^2-6t right - now you just want to solve for t.
Rearranging we get:
3t^2-6t-105 = 0
which is the familiar quadratic form we all know and love.
Here, you can use your (-b +/- square root(b^2-4ac))/2a formula.
a=the t^2 coefficient = 3
b= the t coefficient=-6
c=the constant = -105
so
(-(-6)+/- sqrt ((-6)^2-(4)(3)(-105)))/2(3)
(6 +/- sqrt(36+1260))/6
(6 +/- 36)/6
so your two possible answers are:
7 or -5.
Obviously it cannot take -5 seconds to cross the field, so your answer is 7 seconds.

Thanks!

doc_17

hawaiichair wrote: »

help please?
A farmer ploughs a field with his tractor. The distance of the tractor from the gate of the field after t seconds is given by
s=3t^2 – 6t
(s is in metres)

the distance from the gate to the end of the field is 105 m – how many secs does it take the tractor to reach the end of the field?

I know it's 105=3t^2 – 6t but I can't figure it out after that

Solve the quadratic.

3t2 -6t = 105
3t^2 – 6t - 105 = 0 ( divide by 3)
t^2 -2t - 35 = 0
(t – 7)(t + 5) = 0
So t = 7seconds.

marko93

2004 Paper 1. Q2 C (iii)
For the love of jesus will someone help me work this out
For the life of me i cant do it ¬_¬

AdamD

Sunny!! wrote: »

Why come out with a comment like that and make peope feel worse about it

Cause it amazes me how people can fail such a simple exam.

Platinum2010

how does one do differentiation?

marko93

AdamD wrote: »

Cause it amazes me how people can fail such a simple exam.

If you have nothing positive or any help to add, then leave us be.
We never asked for you to scrutinize us.

J_E

AdamD wrote: »

Cause it amazes me how people can fail such a simple exam.

I'm normally against this kind of talk but I agree with this. You guys don't know how lucky you have it compared to Higher Level. What they ask you on the exam is actually what is asked in books. It's the same thing every time, very predictable and everyone could get at least a B out of this with practice on the questions. You don't even have to fully understand the concepts behind everything.

marko93

Cydoniac wrote: »

I'm normally against this kind of talk but I agree with this. You guys don't know how lucky you have it compared to Higher Level. What they ask you on the exam is actually what is asked in books. It's the same thing every time, very predictable and everyone could get at least a B out of this with practice on the questions. You don't even have to fully understand the concepts behind everything.

Dont mean to be or sound like a cnut... But from just looking at the title i dont think that needs to be said, i dont think they need to hear about something even harder when they're dreading this one alone.. I understand what you're saying I dont HL for awhile. Still. It wont help
BUUUUUUUUUUUUUUUUTTTTTT.
If you want to throw some pointer then by all means feel free

Exothermic

Guys, lay off a bit.
For all those times that you didn't understand something or got stuck, I'm sure you appreciated it when people didn't ridicule you.

GoldFour4

AdamD wrote: »

Cause it amazes me how people can fail such a simple exam.

It amazes me how a parent can name their child adam.

marko93

malachyscott wrote: »

It amazes me how a parent can name their child adam.

Right now, let's not derail the thread.
Keep it on topic.
So yeah intergers..

GoldFour4

marko93 wrote: »

Right now, let's not derail the thread.
Keep it on topic.
So yeah intergers..

Sorry , i feel it was deserved though

Can anyone give me a list of the values of i to the power of 3,4,5,6 etc in complex numbers? Its giving me a hard time.

LilMissCiara

malachyscott wrote: »

Sorry , i feel it was deserved though

Can anyone give me a list of the values of i to the power of 3,4,5,6 etc in complex numbers? Its giving me a hard time.

i squared is -1.

From that break down i to the power of number > 2 in to 2s.

eg.
i^5 = i^2 x i^2 x i = -1 x -1 x i = i.
i^5 => i.

i^6 = i^2 x i^2 x i^2 = -1 x -1 x -1 = -1
i^6 => -1

Hope that helps!

AdamD

malachyscott wrote: »

It amazes me how a parent can name their child adam.

Good one mate

GoldFour4

LilMissCiara wrote: »

i squared is -1.

From that break down i to the power of number > 2 in to 2s.

eg.
i^5 = i^2 x i^2 x i = -1 x -1 x i = i.
i^5 => i.

i^6 = i^2 x i^2 x i^2 = -1 x -1 x -1 = -1
i^6 => -1

Hope that helps!

Thanks a million

marko93

First principles anyone?

GoldFour4

marko93 wrote: »

First principles anyone?

A few basic steps.

1) = Get F(X)
2)= Get F(X+H)
3)= Get F(X+H)-F(X)

4)=Get F(X+H)-F(X)
H

5) = put in o for every value of h

LilMissCiara

marko93 wrote: »

First principles anyone?

Lim h->0 of f(x+h)-f(x) / h

For Sin(x+h)-Sin(x) you change it to 2Cos(2x+h/2)Sin(h/2) (It's in the log tables anyway if that's not 100% right).

Once you have the basic formula it's easy enough to go from there and get a good bunch of the marks.

marko93

malachyscott wrote: »

A few basic steps.

1) = Get F(X)
2)= Get F(X+H)
3)= Get F(X+H)-F(X)

4)=Get F(X+H)-F(X)
H

5) = put in o for every value of h

LilMissCiara wrote: »

Lim h->1 of f(x+h)-f(x) / h

For Sin(x+h)-Sin(x) you change it to 2Cos(2x+h/2)Sin(h/2) (It's in the log tables anyway if that's not 100% right).

Once you have the basic formula it's easy enough to go from there and get a good bunch of the marks.

Thank you so much

Ciara where is it in the log tables?
I couldnt find it

LilMissCiara

marko93 wrote: »

Thank you so much

Ciara where is it in the log tables?
I couldnt find it

It's not in the log tables but its easy to remember!

dy/dx = Lim h->0 of f(x+h)-f(x) divided by h


Write it out a few times to make sure it sticks!

Good luck!

Framble

Are the sequences and series formulas in the tables?

doc_17

marko93 wrote: »

2004 Paper 1. Q2 C (iii)
For the love of jesus will someone help me work this out
For the life of me i cant do it ¬_¬

write everything to base 2

(2^1)(2^2)^1/4 = 2^5-x

(2^1)(2^1/2) = 2^5-x

now ignore base (2)

so....

1+1/2 = 5 - x

x = 5 - 1.5

x = 3.5

Ficheall

marko93 wrote: »

2004 Paper 1. Q2 C (iii)
For the love of jesus will someone help me work this out
For the life of me i cant do it ¬_¬

Apols for delay..

doc_17

Framble wrote: »

Are the sequences and series formulas in the tables?

Yes. Check the table of contents for page no.

Rabbitandcavy

I'm really nervous, I only got 20% in the mocks.
I hate the thought of repeating just because I can't pass a stupid maths exam and did well in everything else.

marko93

doc_17 wrote: »

write everything to base 2

(2^1)(2^2)^1/4 = 2^5-x

(2^1)(2^1/2) = 2^5-x

now ignore base (2)

so....

1+1/2 = 5 - x

x = 5 - 1.5

x = 3.5

That's confusing me
what happened to the 8^1/3 and the 4^1/4
AHHH I DONT GET THIS

Ficheall wrote: »

Apols for delay..

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