Standard Math Q+A Thread

[RuiAce]

Hi.... 
This is probably a dumb question but i can't understand why the answer for Q4 in the 2012 General Maths HSC Paper is A? I got B and can't quite figure out why it is B... here is the link to the paper... it is Q4 and is about the expression used to calculate the value of x in the particular triangle...
https://www.boardofstudies.nsw.edu.au/hsc_exams/hsc2012exams/pdf_doc/2012-hsc-exam-general-maths.pdf
Thanks heaps... very much appreciated!!!!!!!....

But of course you don't want sin in there, because all of their answers have cos in them.
So you need to consider the other angle (the \(40^\circ\) instead)

[jamonwindeyer]

Hi.... 
This is probably a dumb question but i can't understand why the answer for the attached question is A? I got B and can't quite figure out why it is A...
Thanks heaps... very much appreciated!!!!!!!....

Hey! So we know that the cosine ratio is ADJACENT over HYPOTENUSE, think SOHCAHTOA

So, we do that cosine ratio for the angle of 40 degrees in the bottom corner:



Now multiply both sides by 29, the one on the right will cancel, leaving us:



That's where A comes from! Does it help?

[morning_sunshine]

So how would I find the value of A in this instance?

Like I tried making A the subject but that wasn't so successful so what should I do?

Thanks in advance

[britt.jayne]

THANKS SO MUCH!!!!! I ACTUALLY UNDERSTAND NOW!!!!  I was looking at it totally wrong!!!....
i'm really hoping i don't make any stupid mistakes tomorrow!!!!! 
thanks again!!!!!!

[MisterNeo]

So how would I find the value of A in this instance?

Like I tried making A the subject but that wasn't so successful so what should I do?

Thanks in advance

From the graph, you can see that when x(days)=0, the Mass is 1.5. You would sub these into the equation and then solve for A.

[morning_sunshine]

From the graph, you can see that when x(days)=0, the Mass is 1.5. You would sub these into the equation and then solve for A.

MAKES SO MUCH SENSE!
I kept reading m as 1 which is probs why i kept getting it wrong
THANK YOUU

[morning_sunshine]

From the graph, you can see that when x(days)=0, the Mass is 1.5. You would sub these into the equation and then solve for A.

but then how would I find the daily growth rate of the pig?
Like is there a formula or something coz the answers literally just give me the answer

[harry77]

hello
how do i figure the IQR out pls help
thanks

[pvee123]

Is Medicare Levy, tax deductible?

[jamonwindeyer]

hello
how do i figure the IQR out pls help
thanks

Hey! So the \(IQR\) is the middle 50%, or in this case, the middle 200 students. So, we look at the difference in height from the 100 student mark on the cumulative frequency axis, to the 300 student mark (the middle 200 students).

172cm - 136cm = 36cm

This is just like going Q3 - Q1, but we get the values from a graph this is a hard question! Does it make sense?

[jamonwindeyer]

Is Medicare Levy, tax deductible?

Nope, it is an amount you pay on top of your regular tax contribution

[harry77]

thanks so much jamon it finally makes sense now!!

[harry77]

i am having trouble with this can you help pls!!

this question is from last yrs paper,

thanks

[jamonwindeyer]

i am having trouble with this can you help pls!!

this question is from last yrs paper,

thanks

Hey! I don't have the values from higher up to do it numerically, but the idea will be:

VOLUME OF RECTANGULAR PRISM - VOLUME OF 24 SMALL CYLINDERS

You need the volume of the big rectangular prism (used the depth and radius of the marshmallows), and then subtract 24 lots of the volume of the marshmallow. The difference is your chocolate (if this question doesn't make you hungry nothing will)

[harry77]

here is the question from above for the marshmallow one
sorry pls explain further?