Standard Math Q+A Thread

[morning_sunshine]

This is using the cosine rule
a²=b²+c²+2bc cosA
a = BC, b = AC c= AB
Or in other words a= 90, b = c = x
A= 113º
That's how they get the first line
From there they just rearrange it. They get all the terms with x on one side (they already are though), all the terms without on another, then they factor out the x², get x² as the subject then square root both sides

If you're unsure about the cosine rule, you should brush up on it (don't know what's required for your course though) and if you still need help let me know. Rest is just rearranging the equation to make x the subject

The part where I got confused was where there was 2x squared - 2x squared which in the following line became only one 2x squared and a one in the bracket.
Where did the one come from and since they were like terms would those 2x's minus each other and equal 0?

[RuiAce]

The part where I got confused was where there was 2x squared - 2x squared which in the following line became only one 2x squared and a one in the bracket.
Where did the one come from and since they were like terms would those 2x's minus each other and equal 0?

They factorised \(2x^2\) out.

[morning_sunshine]

They factorised \(2x^2\) out.

i know i am going to sound like a pain but could you break down the steps as to how they factorised the 2x squared in the equation for the triangle previously. like I understand they factorised it but I would like it to be broken down so I get a clearer understanding

[RuiAce]

[morning_sunshine]

OMG IT ALL MAKES SENSE!
If I was in an exam though, how would i know that i had to factorise the equation
(I'm super dumb so I really need all the help I can get)

[RuiAce]

OMG IT ALL MAKES SENSE!
If I was in an exam though, how would i know that i had to factorise the equation
(I'm super dumb so I really need all the help I can get)

Given that ultimately we had to make \(x\) the subject, it makes sense to isolate \(x\) first. But in that example, we'd have to isolate \(x^2\) as if we factor out just \(x\), we'd only end up factoring it out again.

So we pull out the \(x^2\), and then we pull the 2 out just because it's a common factor. You need to be capable at spotting common factors, as they're the biggest hint to factorise in a rearranging question.

It's also important to look at what you're trying to aim for. If you didn't realise you had to make \(x\) the subject, you wouldn't be able to spot anything.

[morning_sunshine]

Given that ultimately we had to make \(x\) the subject, it makes sense to isolate \(x\) first. But in that example, we'd have to isolate \(x^2\) as if we factor out just \(x\), we'd only end up factoring it out again.

So we pull out the \(x^2\), and then we pull the 2 out just because it's a common factor. You need to be capable at spotting common factors, as they're the biggest hint to factorise in a rearranging question.

It's also important to look at what you're trying to aim for. If you didn't realise you had to make \(x\) the subject, you wouldn't be able to spot anything.

Thank you so so much!
Final question I promise
So how do I get that 2x squared onto the other side?
Would I multiply it on both sides and then move the 90 across?

[RuiAce]

[jadzia26]

Hey, any suggestions on how to beat silly mistakes?
Although math is one of my strongest subjects i find the really wordy questions throw me and i end up messing up completely and only afterwards ill realise how simple it was. its super frustrating that silly mistakes drag me down a bit 

[Shadowxo]

Hey, any suggestions on how to beat silly mistakes?
Although math is one of my strongest subjects i find the really wordy questions throw me and i end up messing up completely and only afterwards ill realise how simple it was. its super frustrating that silly mistakes drag me down a bit 

Wordy questions can be quite confusing. For worded questions I tend to write down the important information (eg a truck is travelling along a road that is of a length of 20km, I'd write "L=20km"). I'd summarise all the information like this to make it easier to process all the information and see if any formulas would apply.
My tip of the day. I still struggle with silly mistakes though, everyone does so don't worry, you're not alone

[jadzia26]

Whenever I do math papers I always keep the formula sheet next to me!
I find that knowing which parts of the syllabus i need to know and which parts are given to me helps so much and releases stress that just isn't necessary!

[Potatohater]

How do you go about solving 6w^4 X 1/2w^2? I'm having trouble knowing what index law to apply to this

[jamonwindeyer]

How do you go about solving 6w^4 X 1/2w^2? I'm having trouble knowing what index law to apply to this

Hey! This is the index law for multiplication, remember:



The constants will be multiplied together separately, and then we use the index law above for the pro-numeral:



Does this make sense?

[katie,rinos]

Hey Guys,
I've brought the topic tests book for general maths and was wondering if there was a time limit that we should be using for the tests?
Thanks heaps

[jamonwindeyer]

Hey Guys,
I've brought the topic tests book for general maths and was wondering if there was a time limit that we should be using for the tests?
Thanks heaps

Hey Katie! The tests are designed to be done in an hour, but if it ends up being too hard or easy feel free to adjust - Use a time limit that is challenging but still achievable for you, and don't be afraid to make your time limits shorter as you go on