VCE General & Further Maths Question Thread!

[LiquidPaperz]

thanks for that guys, made it quite clear now!

Can anyone explain how/where the second table was source from (attached)


Question: At least two unpowered sites (y) were needed for every powered site (x).  (incase needed)

[kinslayer]

That is just saying that each value of (x,y) in that table satisfies the inequality .

For example, if x = 1 and y = 2, then y >= 2x

if x = 2 and y = 5, then y >= 2x

if x = 3 and y = 10, then y >= 2x

etc, etc.

[LiquidPaperz]

Thanks finally understood this. Last thing is, why is it >= and not <= eg y...2x in the ... Part?

[kinslayer]

In each line, the y-values (2, 5, 10) are greater than or equal to twice the x values (1, 2, 3).

We say when either or . In each case in that table, either y>2x or y = 2x. So we can say that .

[LiquidPaperz]

thanks

[LiquidPaperz]

How do you sketch a objective functions? for example C = 10x + 5y, with other inequalities such as x >= 0,, y >= 0,, x + y >= 8 ....

do we treat it as an equation to graph? or is it an inequality some how? (objective function)

thanks

[keltingmeith]

How do you sketch a objective functions? for example C = 10x + 5y, with other inequalities such as x >= 0,, y >= 0,, x + y >= 8 ....

do we treat it as an equation to graph? or is it an inequality some how? (objective function)

thanks

The equation defines a plane contained somewhere in the x, y and C axis. Now, can you remember the name of the thing you draw graphs on with an x and y axis? If you guessed Cartesian plane, and then realised you have a problem, you're right.

So, the equation would actually involve colouring in the whole Cartesian plane in front of you. However, the other inequalities fix this - if we have those other constraints, then the objective function will only be defined in the intersection of those other constraints.

[Billion]

Hi guys, need help.
How can you tell when the two coincide for the first time using numbers?
The answer is at the 24th bar.
I used my CAS to calculate each sequence up to their 24th bar, and when looking at the two numbers from either sequence I didn't see any relevance.

Thanks in advance.

[Jono_CP]

Any Business Maths resources which will help me reach agonisingly close to a pass but with dignity for my SAC on Friday???

[keltingmeith]

Hi guys, need help.
How can you tell when the two coincide for the first time using numbers?
The answer is at the 24th bar.
I used my CAS to calculate each sequence up to their 24th bar, and when looking at the two numbers from either sequence I didn't see any relevance.

Thanks in advance.

Okay, so the question is a rather confusing one - let's just differentiate what each part means and change the symbols up a bit:

We'll let be the sequence we use for the crash cymbals, and be the sequence we use for the timpani rolls. Now, refers to the how much the instrument has already sounded - i.e., the th sound. Now, the value that and take on are the bar in which the sound occurs.

So, what we want is to find the first point when , and whatever value that is is our answer. Now, we note that must be a multiple of three, since we start with 3 and keep doubling it, whereas is an arithmetic sequence, and so could take any value. So, we will take , and keep calculating values until we have a multiple of three, and that should be our answer. We will then double check this against , since not every multiple of three will appear:




And so, we see that both sequences first take on the same value of 24, which is the bar that they first play together. The fact that they are at different positions only means that the cymbals have sounded more than the timpani at the time of this co-incision.

[Billion]

Number patterns question. Solutions provided.
Can someone explain to me how they got they answer b = 5?

Also, their solutions figure out a = 0.90 by doing another method.
Is it acceptable to use the information that 'a' is found by "reducing usage deficit by 10% compared with the prev month", therefore a = 1 - (10/100) = 0.90?

Thanks in advance.

[plato]

Number patterns question. Solutions provided.
Can someone explain to me how they got they answer b = 5?

Also, their solutions figure out a = 0.90 by doing another method.
Is it acceptable to use the information that 'a' is found by "reducing usage deficit by 10% compared with the prev month", therefore a = 1 - (10/100) = 0.90?

Thanks in advance.

Is there more information prior to this question? There seems to something missing, aside from the possible cause of Elmo's sex change during the question.

[LiquidPaperz]

in a similar triangles question, if two lines are parallel what does this tell us and how can this tell us when solving the question?

Like with this question, i know how to do it, but being parallel does it help me in any way? does it mean i can/can't do a certain method ?

Thanks

[AngelWings]

in a similar triangles question, if two lines are parallel what does this tell us and how can this tell us when solving the question?

Like with this question, i know how to do it, but being parallel does it help me in any way? does it mean i can/can't do a certain method ?

Thanks

The lines being parallel confirm that the bottom two corners of both triangles are the same.
Without that being said, the angles could have easily been different and thus, not similar.

If you want me to be more detailed about this answer, just say so and I'll try to explain it better.

[LiquidPaperz]

thanks for that!! is their anything else you could add please?

thanks