Labelling co-ordinate axes (1 Viewer)

[kpq_sniper017]

Probably the most basic question that I should've asked in Yr8, but in the HSC, is it necessary to label the axes (1,2,3,4......)? Coz I find that in the exam it's just a waste of time. Is it sufficient to leave the lines blank, label X,Y and then just write the necessary points?

 

[pc_wizz]

i normally mark several ordinates onto the axis ... usually the most necessary pts

pcwizz

 

[...]

yea, just write the necessary pts

(ie turning pts, max, min, stationary etc etc)

 

[clerisy]

I agree.

On a similar topic, are we supposed to stick arrows on our graphs to show that it goes on in that vein for infinity (that is, on those that do)? I always have, but I noticed the other day that nobody else in my class do, and neither do the textbooks. I don't thiink it really matters-- they're obviously not going to mark you down for putting arrows on (or not putting arrows on)-- but I need to know the truth! What is supposed to be done?

 

[Estel]

Arrows = good habit.

 

[:: ck ::]

dont bother drawing lines for each coordinate.. eg : 1,2,3,4,5,6, blah blah

just mark the important pts... and label those parts on the axis ...

and u shud always have arrows on ur graphs..... and label the x and y axis... as a habit

 

[kpq_sniper017]

Originally posted by :: ryan.cck ::
dont bother drawing lines for each coordinate.. eg : 1,2,3,4,5,6, blah blah

just mark the important pts... and label those parts on the axis ...

and u shud always have arrows on ur graphs..... and label the x and y axis... as a habit

so does it matter if ur graph doesn't have a particular scale along the x or y axes?

would u get marked down for:
a) not laying out the axes properly i.e. not labelling etc.
or
b) not having arrows etc....?

 

[Xayma]

Well considering 95% of the time it says sketch you shouldnt need to mark the points (and when it says sketch you dont have to have a very accurate scale)

Arrows and labelling the axis x and y should become a habit.

 

[:: ck ::]

Originally posted by pcx_demolition017
so does it matter if ur graph doesn't have a particular scale along the x or y axes?

would u get marked down for:
a) not laying out the axes properly i.e. not labelling etc.
or
b) not having arrows etc....?

as for having a proper scale... i dont think it matters too much.. as long as it doesnt affect the shape of ur graph dramatically ...

as for arrows n stuff.. no i dont think u wud lose a mark... but still, do it anyway ... mayb some markers are bitchy in 2u and are less leniant.. i dunno

but say u had to draw a graph y=2cos(2x-pi/2) ... if u had no idea... and just drew the axis.. u wouldnt get any marks at all ..

 

[kpq_sniper017]

Originally posted by Xayma
Well considering 95% of the time it says sketch you shouldnt need to mark the points (and when it says sketch you dont have to have a very accurate scale)

Arrows and labelling the axis x and y should become a habit.

with the arrows....are these the arrows at the end of the axes or at the end of the curves? .... if so, u'd only put arrows on a continuous curve wouldn't u?

 

[Xayma]

Put the arrows on the axes, and on continuous curves, and always label the curve with its equation.

 

[Calculon]

I think you only need to put the arrows on one end of each axis as well

 

[kpq_sniper017]

ok..
i've always labelled graphs/axes etc.
but i've never put arrows on the end of curves...i guess i should get into the habit of it now.

 

[Wild Dan Hibiki]

should it be to scale? cause if u only mark important points then it wouldn't be to scale

 

[charmed_cuties]

the x and y axis dont have to be to scale to 1 another
my teacher scribbles over our exam papers telling us to label axis and wen we do curve sketching examples she keeps on reminding us over and over again!

 

[:: ck ::]

for continuous curves it is not really required to put arrows on the ends of the curve...

as the hsc solutions don't ... well that's what i heard from somebody anyway ...

 

[kpq_sniper017]

Originally posted by :: ryan.cck ::
for continuous curves it is not really required to put arrows on the ends of the curve...

as the hsc solutions don't ... well that's what i heard from somebody anyway ...

ok.
one other thing....with a graph like tan^-1x + tan^-1(1/x), would u be marked down if u forgot to draw open circles on the y-axis at the end of each horizontal line?

 

[CM_Tutor]

Originally posted by pcx_demolition017
ok.
one other thing....with a graph like tan^-1x + tan^-1(1/x), would u be marked down if u forgot to draw open circles on the y-axis at the end of each horizontal line?

I would, because it suggests that y = tan^-1x + tan^-1(1 / x) is defined for x = 0, which it isn't, and furthermore that it isn't a function, which it is.

On the wider question, exact scales aren't necessary, but all should keep diagrams roughly to scale, and also have approriate features. For example, when sketching y = sqrt(4 - x<sup>2</sup), the sketch should appear vertical at the x-intercepts, horizontal at the y-intercept, and it should appear symmetrical about the y-axis (ie. even).