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#3 Re: Help Me ! » Real life applications for every math concept » 2018-06-11 12:52:10

bob bundy wrote:

You may not realise it, but every time you put in your on-line bank password, or send your credit card details, you are relying on prime number theory.

Ummm... Can you explain?

#6 Re: This is Cool » Miscellany » 2018-06-09 12:40:35

ganesh wrote:

(The name may be somewhat of a misnomer - game theory generally does not share the fun or frivolity associated with games.)

So that's why I never enjoy learning about game theory.

#20 Help Me ! » Ask About Annuity » 2018-05-15 21:33:55

Monox D. I-Fly
Replies: 1

Mr. Budi borrows 2,000,000IDR which will be amortized with 10 annuities. The first annuity will be paid in 1 year with 10% per year interest. Make the installment plan!
For the annuity I got A =

=
=
=
=

(
is a geometric sequence with the first term
and ratio
)
=
=
= 2,000,000 × 0.61445671 = 1,228,913.42
Thus, the annuity is 1,228,913.42.
On the end of first year:
Annuity = 1,228,913.42IDR
Interest : 10% × 2,000,000IDR = 200,000IDR
Installment : 1,228,913.42IDR – 200.000IDR = 1,028,913.42IDR
Remaining loan : 2,000,000IDR – 1,028,913.42IDR = 971,086.58IDR
On the end of second year:
Annuity = 1,228,913.42IDR
Interest : 10% × 971,086.58IDR = 97,108.66IDR
Installment : 1,228,913.42IDR – 97,108.66IDR = 1,131,804.76IDR
Remaining loan    : 971,086.58IDR – 1,131,804.76IDR = -159.718,58IDR
Why am I seeing negatives already?

#21 Help Me ! » [ASK] Fraction Addition with Arithmetic Series as Denominators » 2018-05-14 14:00:16

Monox D. I-Fly
Replies: 1

Does anyone know how to add these fractions?


Like my previous question, I believe this one also has something which can be canceled out, and the denominators contain arithmetic series. Can this series be used to make some sorts of shortcuts?

#22 Help Me ! » [ASK] Fraction Addition » 2018-05-14 13:50:52

Monox D. I-Fly
Replies: 1

Does anyone know how to add these fractions?


I believe making them in
form isn’t the correct approach.
Is there anything we can cancel out?

#23 Re: Help Me ! » Vectors and Planes » 2018-05-11 15:59:26

Any idea how to answer number 4? I tried kx + z = y + kz and got this:
kx – y + z – kz = 0
kx – y + (1 – k)z = 0
To make the system have no solution or infinite amount of solutions, I think kx – y + (1 – k)z is a multiple of -2x + 4y + z thus I multiplied it by -4 and got -4kx + 4y + (-4 + 4k)z = 0. From the x coefficient, I got k = 1/2, but from the z coefficient I got 5/4. Different answers. Was what I do wrong? What is the proper way to solve it? Thanks.

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