Standard Math Q+A Thread

[aimbotted]

Hey Nicole! In addition to Jamon's post (which I thank him for), these are some capacity formulas worth knowing

Hope that all helps 

hey op, i thought 1m^3 was 1000 liters, which in turn was 1 kilo liter

[stephanieazzopardi]

hey op, i thought 1m^3 was 1000 liters, which in turn was 1 kilo liter

Yes sorry you're right!

[jamonwindeyer]

Yes sorry you're right!

I have made that fix above!

[kmorritt]

Hi kmorritt, was going to post a 'General Math' friendly explanation, but it seems that you understand their explanations so I'm very glad Please keep asking questions if need be, and good luck!

Hi stephanieazzopardi, thank you anyway. Yes will do

[sarah.murphy]

Hi General Mathematicians   
I have an issue... i love spherical geometry but... it always confusing me when we come to times zones whether I have to plus (+) or minus (-) the hours!!!  can someone please explain it in layman's terms.
Please and thank you!

[RuiAce]

Hi General Mathematicians   
I have an issue... i love spherical geometry but... it always confusing me when we come to times zones whether I have to plus (+) or minus (-) the hours!!!  can someone please explain it in layman's terms.
Please and thank you!

Remember that all time zones are based off a thing called the "prime meridian" in Greenwich, England. That's the universal time centre - GMT +0

The more to the east we go, the more hours we add.
The more to the west we go, the more hours we minus.

So if we go 15^o to the east of Greenwich, we add 1 hour on.
If we go 30^o to the west of Greenwich, we subtract 2 hours off.


Same applies in Australia. Ignoring daylight savings time for this purpose, if we go from Sydney to Perth, which is 30^o west, we subtract 2 hours off.

Also remember that in total, you only have 180^o east or west at most

[aimbotted]

Do we need to know that compound formula where you add period installments to it? Can't seem to find it in my textbook yet its relevant in the HSC past exams.

[RuiAce]

Do we need to know that compound formula where you add period installments to it? Can't seem to find it in my textbook yet its relevant in the HSC past exams.

Do you mean annuities? There's some information about it in page 76 of the syllabus, but I'm not entirely sure in how much depth you need to know it though.

The future value formula for an annuity doesn't seem to be in your formula sheet explicitly.

[aimbotted]

nop, annuities are okay but its this formula or whatever it's called

[RuiAce]

nop, annuities are okay but its this formula or whatever it's called

That's just the annuity formula in disguise. One of them is the FV whereas the other is the PV

Reading the question, it would appear that 12000 is the future value of the annuity. Hence we are interested in the formula


Note that the above formula is for when our deposits are all $1. Because we deposit $M each month, not $1, we have an M in front of the fraction.

Also, the interest is compounded monthly.
Hence r=0.005 and n=12*10=120

I think the answer is D.

[aimbotted]

hey thanks for that! but i just asked my teacher and he said that it was removed from 2013 and forward.

thanks again.

[RuiAce]

That makes sense. The formula was explicitly stated on the old formula sheet it seems.

You may want to consider PastHSC for a mapping grid of what's relevant in the current HSC exams and what's outdated, (For HSC papers before 2014)

[stephanieazzopardi]

nop, annuities are okay but its this formula or whatever it's called

Hi aimbotted! I can assure you that you will never be asked to use such formulas for annuities. You will always be given a table of annuities, you will never have to work out the annuity/contribution factor yourself!

[AngelicOnyx]

Hi aimbotted! I can assure you that you will never be asked to use such formulas for annuities. You will always be given a table of annuities, you will never have to work out the annuity/contribution factor yourself!

Oh my god you just saved me. I've been trying to do a past paper with one of those questions and nearly had a mental breakdown because I had absolutely no idea what to do 

[sarah.murphy]

Remember that all time zones are based off a thing called the "prime meridian" in Greenwich, England. That's the universal time centre - GMT +0

The more to the east we go, the more hours we add.
The more to the west we go, the more hours we minus.

So if we go 15^o to the east of Greenwich, we add 1 hour on.
If we go 30^o to the west of Greenwich, we subtract 2 hours off.


Same applies in Australia. Ignoring daylight savings time for this purpose, if we go from Sydney to Perth, which is 30^o west, we subtract 2 hours off.

Also remember that in total, you only have 180^o east or west at most

Oh okay, yes yes. So it is sort of like which direction we are travelling  from a place?
Thank you so much!