Standard Math Q+A Thread

[Shadowxo]

Could someone walk me through how to get the answers to the following questions.

1) (Image removed from quote.)

2) (Image removed from quote.)

3) (Image removed from quote.)

4) (Image removed from quote.)

5) (Image removed from quote.)

Thank you!!

1. The interest per month is 8/12 = 0.666667%
Future value = initial amount * (1+growth rate)ⁿ
= 5000*(1+0.00666667)³⁶ =D   (n = 36 months)

5. Is just rearranging

Note we don't have the ± as length can't be negative

[EEEEEEP]

Could someone walk me through how to get the answers to the following questions.

1) (Image removed from quote.)

3) (Image removed from quote.)
Thank you!!

[Shadowxo]

3. Alternatively (good solution E6P though) we could use the graph
The graph is saying if you deposit $1 per period at an interest rate of r% per period, what the present value is
We know the interest rate is 4% per year so that means 2% per half year (interest compounded bi-annually)
There are 6 periods (6 half years in 3 years)
So $1 deposited per half-year at 2% per period is worth $5.601. Multiply it by 9000 (the amount deposited per half-year) and you get the same answer D

[RuiAce]

(Image removed from quote.)

3. Alternatively (good solution E6P though) we could use the graph
The graph is saying if you deposit $1 per period at an interest rate of r% per period, what the present value is
We know the interest rate is 4% per year so that means 2% per half year (interest compounded bi-annually)
There are 6 periods (6 half years in 3 years)
So $1 deposited per half-year at 2% per period is worth $5.601. Multiply it by 9000 (the amount deposited per half-year) and you get the same answer D

They don't use annuity formulae nor have annuity methods. They must read a table that's been given to them.
________________

To read the table, the annuity factor is dependent on r and n.
n is the number of periods, and is equal to 6 as we deposit twice every year, for three yaers.
r is the rate per half-annum. 4% per annum becomes 2% per half year.

The annuity factor gives the present value of just $1. So if we want the present value of $9000 we have to multiply 9000 to that value on the table.

(That being said, I am very much annoyed at how they use "compounded biannually" to represent what's actually "semi-annual compounding". I have no idea where the logic works here.)

[EEEEEEP]

(That being said, I am very much annoyed at how they use "compounded biannually" to represent what's actually "semi-annual compounding". I have no idea where the logic works here.)

It's an outdated term, but biannually has its roots in latin. Bi = two, So...... biannually = two times  a year =)

[RuiAce]

It's an outdated term, but biannually has its roots in latin. Bi = two, So...... biannually = two times  a year =)

The way I interpret compounded biannually is that I see bi as a prefix before the word "annual". So when I see this, I don't think compounded twice per year, but rather once per two years.

But if it is outdated, I sincerely hope it stays outdated.

[stephanieazzopardi]

Compounded biannually means compounding twice per year.

[emilybrooks99]

Thank you so much!!!

[katie,rinos]

Hey guys,
Could you please help with sections 2 and 3 of this question?
Also, might seem like a dumb question but what mode does the calculator need to be on to do the least-squares line of best fit? How do I get on that mode (I'm using the blue sharp calculator)?
Thanks so much!!

[Shadowxo]

Hey guys,
Could you please help with sections 2 and 3 of this question?
Also, might seem like a dumb question but what mode does the calculator need to be on to do the least-squares line of best fit? How do I get on that mode (I'm using the blue sharp calculator)?
Thanks so much!!

So we know sin(ABC)=8/10 = 4/5 from i)
I'm assuming you're supposed to know the sin rule here

iii) You probably have to use a calculator here, using results from i) and ii) to find the angle

Good luck, let me know if you're still struggling with iii)

[katie,rinos]

So we know sin(ABC)=8/10 = 4/5 from i)
I'm assuming you're supposed to know the sin rule here

iii) You probably have to use a calculator here, using results from i) and ii) to find the angle

Good luck, let me know if you're still struggling with iii)

Thanks so much, that definitely helped with part 3. I'm just a little bit confused, how did you get from the first to the second line of working out for the question (the 6 sin (ABP)/5)

[RuiAce]

Thanks so much, that definitely helped with part 3. I'm just a little bit confused, how did you get from the first to the second line of working out for the question (the 6 sin (ABP)/5)

[morning_sunshine]

Hey guys

I need help with working out the question... like how do I find the equation of the line?
Used the formula of y=mx+b but still didnt make sense...

Thanks in advance

[RuiAce]

Hey guys

I need help with working out the question... like how do I find the equation of the line?
Used the formula of y=mx+b but still didnt make sense...

Thanks in advance

If you tried using that form, check that you found m=-1 and wrote down from the graph that b=2. You need to recall what m and b actually mean in that equation

[EEEEEEP]

- y= mx + b
y = equation of a line
m = gradient
b = y intercept
...........
The Y intercept  (AKA b) is 2 (where the coordinate is 0,2).. b
Gradient = (y2 - y1)/(X2-X1)

Let point 1 = 0, 2
Let point  2 = 2, 0

m = (0--2)/(2-0) = -1

THerefore, the line... y = 2 - x
...
P.S. You can check your answer and see if it fits properly on the cartesian plane