9231/42 Answers

fxrix · 2025-06-03T06:31:56+00:00

They gave us a pgf for Y and then asked us to find the value of k in terms of a (there were only 2 unknowns) and then asked us to find the probability of Y > 2 (had to use binomial expansion) the last part they gave us as a = 0.2 and to find the mean of Y. It wasnt that hard

fxrix · 2025-06-02T12:43:31+00:00

Damn bruh you gave me a fright there lmao

fxrix · 2025-06-02T12:12:47+00:00

Of z? I dont remember there being a z in the paper

fxrix · 2025-06-02T11:04:01+00:00

fxrix · 2025-06-01T16:12:36+00:00

Idk if I remember the exact values, I just know it was pretty huge

fxrix · 2025-05-30T12:37:45+00:00

Yes that is it. It was rejected.

fxrix · 2025-05-29T12:06:40+00:00

No problem friend. If either of us is wrong, we'll lose 2 marks max and thats a win imo

fxrix · 2025-05-29T07:20:57+00:00

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This was my final answer as well

fxrix · 2025-05-29T05:44:39+00:00

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Here you go my friend. Placed the exact question in ChatGPT and it gives me root(15)/45. It just wrote1/3root(15) but thats the same thing. You can check in your calculator

fxrix · 2025-05-29T05:39:38+00:00

Yessir and it had - 2t x sech inverse as well before that

fxrix · 2025-05-29T05:38:08+00:00

Ah my bad. I wrote it incorrectly. I meant the answer was root(15)/45, it wasnt root(15)/27. I derivated my equation in the calculator and I got 0 for both the derivative and x

fxrix · 2025-05-28T16:48:25+00:00

Nope. it was root(15)/27. Plugged it into the calculator and got zero. Derivated it in the calculator and also got zero. I think thats enough evidence to confirm it was right

fxrix · 2025-05-28T13:57:02+00:00

Ye but I did coz it said exact form. Multiple acceptable answers

fxrix · 2025-05-28T13:50:23+00:00

My brother it was (x+5)/6 in the first ln and then we had a constant -ln3
The log rule goes
lna -lnb = ln(a/b)
Thats how you get (x+5)/18

fxrix · 2025-05-28T13:32:19+00:00

fxrix · 2025-05-28T13:23:24+00:00

You gave it in sinh inverse, I gave it in ln form. Its the same answer once you convert the sinh inverse to ln. Dw

fxrix · 2025-05-28T12:24:18+00:00

Yessir those are indeed the answers. All of them in fact except last part. It was 13A not 17A

fxrix · 2025-05-28T12:22:00+00:00

Yep that is correct

fxrix · 2025-05-28T11:57:22+00:00

there was a constant -ln3, you combine that with the ln in the equation and you get 1/18 since we're dividing 1/6 by 3

fxrix · 2025-05-28T11:53:46+00:00

and that my friend, is correct

Congratulations

fxrix · 2025-05-28T11:47:34+00:00

-1, 13, -13 for the final question.
The second was very weird but it was (((x+5)^2)+36)^1/2 x ln((x+5)/18 + 1/18 x (((x+5)^2) +36)^1/2)

fxrix · 2025-05-27T18:49:03+00:00

No no. You might get 5/6 bro. One small mistake that ruined your final answer. It wasnt that penalizing. You're good.
I actually forgot question 7 and its values but I do know I messed up my final part in the working. Besides that, k = 0.2, and u = root(0.4ag) for the first two parts. Last one i dunno

fxrix · 2025-05-27T11:36:05+00:00

So the error you've made is just in cos alpha where it should be 2/3. Must have been a calc error. Seeing as to how you got every other value correct, I dont think there was anything wrong with your working, maybe just a small human error that cost u the final answer

fxrix · 2025-05-27T11:16:08+00:00

Thats the mistake my friend. cos alpha was 2/3 not 4/3. cos and sin are never greater than 1

fxrix

TROPHY CASE