please help with my daughters studying.

ShambleS1980

ShambleS1980

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Hello..
Been a while (sorry about that i have been busy irl)


any way i have a problem, so i will just go ahead and type it out..

SO... my eldest is coming up to her gcse maths exam, and has only just informed me that she has difficulty with some of the questions.

an example of a question she has difficulty with is a 2 part question as follows:

" Michelle has been given 6 equations and has been asked to draw 6 graphs. Before starting, she looks at the equations.

y = 3x
y = x
y = 1/2 x
y = 2x +5
y = 4x +2
y = 2x +4
(please note that x is the letter x not the multiple symbol)

(a) Michelle says 'the steepest graph will be y = 2x +5'.
Is Michelle correct?
You must give a reason for your answer,


(b) Michelle says 'No 2 graphs will be parallel to each other'.
Is she correct?
You must give a reason for your answer.


--------------------------- "


Can any 1 explain how you would work out this type of question, as i don't know how too, and neither does she. She is busy asking people for "the answer"
Which really wont help at all, as what she really needs to know is how you work it out...

There are no values given for "x" and i cant seem to find any way to calculate what it should be..

Thought id come ask here as most here are pretty good with maths.:thumbsup:
 
if im reading it right,with a and the graph would look like a steep incline.
 
Quicky before home:
The shape of the graph is determined by the 2x, 3x etc. The higher the number the "steeper" the graph.

The position is determined by the "+". If you add to the result, the graph will move up, subtract, the graph will move down.

In these equations, X is not a constant.

You need a piece of graph paper, with (for example) -10 to 10 drawn across, and -10 to 10 drawn up and down. The two lines should form a cross, with the two zeros together:

Code: 
    | (Y)
    |
    |
----+---- (X)
    |
    |
    |

The up/down is referred to as Y, the across is X.

For all values of X, you need to work out Y... so,

assuming y=3x

When x = -10, you need to plot a point where across is -10, and up/down is -30 (3*-10)
When x = -9, you need to plot a point where across is -9, and up/down is -27 (3*-9)

You should see the points forming a line.


Code: 
    | (Y)
    |  .
    | .
----+---- (X)
   .|
  . |
 .  |

Drawing graphs for all the equasions auto to show her what the number before X does to the line (makes it steeper), and what the + does (moves it up and down)
 
These are all straight line graphs. The figure in front of the x is the gradient, and the second figure (without an x) is the point it crosses the y axis.

The steepest graph has the highest gradient so 4x is the steepest. this is because it goes up 4 units (on the y axis) for every 1 unit it moves along the x axis.

2 graphs WILL be parallel, as y=2x +4 and y=2x+5 have the same gradient, but cross the y axis at different points.

Thats all as far as I can remember and reckon by the time I hit submit someone smarter will have answered anyway!

EDIT - I knew others would answer first but Chinners keeps adding to his post so it looks like he did it all straight away!:p

OK - check my attachment! (Just ignore the part of the legend that says "x" on its own.
 

Attachments

  • graph.jpg
    graph.jpg
    43.9 KB · Views: 1
Last edited:
i knew i could count on you guys..

no idea why i was'nt thinking axies when i saw Y and X

thanx a lot!:thumbsup:
 
I'm with you Shambles, where's the x value?

But to be fair, why do they still teach confusing rubbish which nobody would ever use in the real world?
 
Ed.D said:
I'm with you Shambles, where's the x value?

But to be fair, why do they still teach confusing rubbish which nobody would ever use in the real world?
Click to expand...


there are a few trades that would require these sort of maths skills,say roofers and joiners for instance.



i thought x was equal to y,i know theres a line on the graph marked x but i dont know why its there in post #4 but the rest looks spot on.
 
roy_bates said:
i thought x was equal to y,i know theres a line on the graph marked x but i dont know why its there in post #4 but the rest looks spot on.
Click to expand...

Yeah there was a slight glitch with my excel chart :picard (which is why I added the line to my post saying to ignore that bit!)
 
CrazyC said:
roy_bates said:
i thought x was equal to y,i know theres a line on the graph marked x but i dont know why its there in post #4 but the rest looks spot on.
Click to expand...

Yeah there was a slight glitch with my excel chart :picard (which is why I added the line to my post saying to ignore that bit!)
Click to expand...




i was actually sitting here with pencil and paper drawing it out,and i thought bugger this, these two are using spreadsheets:lol:
 
Just remember, there are lies, damned lies and spreadsheets...



:lol:
 
You can solve the questions without drawing the graphs. (Anything to avoid drawing graphs! :lol:)

They're all of the form

y = mx + c

The steepest graph is represented by the largest value of m, so in this case is y = 4x + 2.

You can identify graphs that will run parallel with each other if they have the same value of m, so in this case y = 2x + 5 and y = 2x +4 will run parallel to each other.

:thumbsup:
 
RichyV said:
AndyLandy said:
y = mx + c
Click to expand...
:arms

Equation of a Straight Line.

Wondered when someone would mention it...
Click to expand...


A, somewhat, related joke:

Once upon a time there was Jesus and called Peter and he said to him
- Peter, y=x^2
Peter was confused about it and asked.
- Lord, what is that?
- A parabel, Peter..


*Hopping on the english language dead body.:bounceBoingBall:
 
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