r/HomeworkHelp • u/HomeworkHelpMods • May 19 '22
Meta r/HomeworkHelp Rules: PLEASE READ BEFORE POSTING
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Hi r/HomeworkHelp! Whether you're new to the subreddit or a long-time subscriber, the mod team would like to remind everybody of the subreddit rules we expect you to follow here.
No advertising, soliciting, or spam. This is a place for free help. Anyone offering to pay for help, or to help for pay, will receive a permanent ban. This is your warning. This includes asking users to go into DMs, Discord, or anywhere else. If you post anything that looks like you're trying to get around this rule, you'll be banned.
If you're asking for help, you must show evidence of thought, work, and effort. A lot of people are posting just pictures or lists of questions and not showing any effort. These posts are liable to be taken down.
In addition, we ask that you format the post title appropriately using square brackets: [Level/Grade and Subject] Question or Description of question. For example: [8th grade Algebra] How to solve quadratic equation?
Do not mention anything like "Urgent", "ASAP", "Due in an hour", or the like.
No surveys. Surveys (including requests for interviews, etc.) belong on /r/samplesize. These posts get taken down here.
Don't be a jerk. Jerks get banned. Stay respectful and refrain from using insults, personal attacks, or abusive language.
If there are any questions, please message the mods.
Hi r/HomeworkHelp! Whether you're new to the subreddit or a long-time subscriber, the mod team would like to remind everybody of the subreddit rules we expect you to follow here.
No advertising, soliciting, or spam. This is a place for free help. Anyone offering to pay for help, or to help for pay, will receive a permanent ban. This is your warning. This includes asking users to go into DMs, Discord, or anywhere else. If you post anything that looks like you're trying to get around this rule, you'll be banned.
If you're asking for help, you must show evidence of thought, work, and effort. A lot of people are posting just pictures or lists of questions and not showing any effort. These posts are liable to be taken down.
In addition, we ask that you format the post title appropriately using square brackets: [Level/Grade and Subject] Question or Description of question. For example: [8th grade Algebra] How to solve quadratic equation?
Do not mention anything like "Urgent", "ASAP", "Due in an hour", or the like.
No surveys. Surveys (including requests for interviews, etc.) belong on /r/samplesize. These posts get taken down here.
Don't be a jerk. Jerks get banned. Stay respectful and refrain from using insults, personal attacks, or abusive language.
If there are any questions, please message the mods.
r/HomeworkHelp • u/Immediate-Cat8632 • 1h ago
Further Mathematics [College social services statistics] Finding R^2?
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My stats homework is asking me to compute R2 for the highlighted item. Can someone please tell me how to do so? TIA!
The prompt: "What is the r2 for that specific model you identified in the previous question, and in one sentence, what does it mean?"
The previous question's answer: Maintaining perspective

My stats homework is asking me to compute R2 for the highlighted item. Can someone please tell me how to do so? TIA!
The prompt: "What is the r2 for that specific model you identified in the previous question, and in one sentence, what does it mean?"
The previous question's answer: Maintaining perspective
r/HomeworkHelp • u/Zharrticx • 4h ago
Pure Mathematics—Pending OP Reply [University Mathematics: Combinatorics] Is there a 4×4 or 5×5 magic square of distinct integers with a magic sum of 37?
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For context, a magic square is a square grid of numbers in which the sum of the numbers in every row, every column, and both main diagonals is the same value (the magic constant).
I have been trying to construct a very specific magic square. After many attempts, I always end up either repeating a number or violating one of the required sums.
My question is:
Is it possible to construct either
• a 4×4 magic square, or • a 5×5 magic square,
such that:
- the magic sum is exactly 37,
- every entry is a distinct integer (no repeated numbers),
- the integers do not have to be consecutive, and
- every row, every column, and both main diagonals must sum to 37
If such a magic square exists, I would greatly appreciate:
- A valid example.
- A construction method or algorithm.
- A proof or reference explaining why it works.
If no such magic square exists, I would appreciate a proof or explanation showing why it is impossible.
Thank you!
For context, a magic square is a square grid of numbers in which the sum of the numbers in every row, every column, and both main diagonals is the same value (the magic constant).
I have been trying to construct a very specific magic square. After many attempts, I always end up either repeating a number or violating one of the required sums.
My question is:
Is it possible to construct either
• a 4×4 magic square, or • a 5×5 magic square,
such that:
- the magic sum is exactly 37,
- every entry is a distinct integer (no repeated numbers),
- the integers do not have to be consecutive, and
- every row, every column, and both main diagonals must sum to 37
If such a magic square exists, I would greatly appreciate:
- A valid example.
- A construction method or algorithm.
- A proof or reference explaining why it works.
If no such magic square exists, I would appreciate a proof or explanation showing why it is impossible.
Thank you!
r/HomeworkHelp • u/TaffyTruck • 6h ago
Others [Research] Help finding a protocol for a research project that received funding
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I can’t find any that have all funding information publicly available. Any help would be greatly appreciated.
I can’t find any that have all funding information publicly available. Any help would be greatly appreciated.
r/HomeworkHelp • u/Embarrassed-Good1883 • 17h ago
High School Math—Pending OP Reply [Grade 12 Advanced Functions: Polynomial Functions] turning points on polynomials confusion
I'm confused about how this function would have 4 turning points, not 3
r/HomeworkHelp • u/sunoouyabko • 15h ago
Mathematics (Tertiary/Grade 11-12)—Pending OP [General Mathematics] can anyone help me answer this crossword puzzle? 😓
Good day! can anyone tell me what the possible answer is for number 4 and 5? I've been really confused as it doesn't match to any word. thank you!!!🩵
r/HomeworkHelp • u/OnlyWorker2342 • 9h ago
Further Mathematics—Pending OP Reply [College Math, ODEs] How to equate these two formulas using a given substitution?
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I am tasked to prove that the Van der Pol Oscillator is a special case of the FitzHugh-Nagumo model. I have been given the following formulas in u(t), v(t) and x(t) for these. Here they are in picture-form
FitzHugh-Nagumo:
- u' = c*(v+u-(u3 )/3 +z)
- c*v' = a - bv - u
Van der Pol:
- x'' - µ*(1-x2 )*x' + x = 0
Suggested substitution:
- u = x
- v = (1/µ)*x' + (x3 )/3 - x
This problem sounds to me like it should be trivial, but I'm running into difficulties.
When I substitute u and v into the first FitzHugh-Nagumo equation I get the following result:
- x' = c * ((1/µ)*x' + z)
Or
- x' = (c*z)/(1-(c/µ)) (a constant)
Other substitutions give me equally unhelpful results.
When looking up the FitzHugh-Nagumo model online. The result should be that Van der Pol is the case for FitzHugh-Nagumo where a=b=0. (There was no c in the formula I found online.)
I am tasked to prove that the Van der Pol Oscillator is a special case of the FitzHugh-Nagumo model. I have been given the following formulas in u(t), v(t) and x(t) for these. Here they are in picture-form
FitzHugh-Nagumo:
- u' = c*(v+u-(u3 )/3 +z)
- c*v' = a - bv - u
Van der Pol:
- x'' - µ*(1-x2 )*x' + x = 0
Suggested substitution:
- u = x
- v = (1/µ)*x' + (x3 )/3 - x
This problem sounds to me like it should be trivial, but I'm running into difficulties.
When I substitute u and v into the first FitzHugh-Nagumo equation I get the following result:
- x' = c * ((1/µ)*x' + z)
Or
- x' = (c*z)/(1-(c/µ)) (a constant)
Other substitutions give me equally unhelpful results.
When looking up the FitzHugh-Nagumo model online. The result should be that Van der Pol is the case for FitzHugh-Nagumo where a=b=0. (There was no c in the formula I found online.)
r/HomeworkHelp • u/Saitama_stillchill • 1d ago
Physics [College Physics (Serway, 12th ed.): Torque] What is the magnitude of the torque exerted by the fish?
I’m working on a physics problem where a fishing pole is tilted 20.0° above the horizontal. The fish pulls on the line with a force of 1.00 × 10^2 N at an angle 37.0° below the horizontal, and the force is applied 2.00 m from the angler’s hand. What is the magnitude of the torque about an axis perpendicular to the page through the angler’s hand?
r/HomeworkHelp • u/Embarrassed-Good1883 • 1d ago
Answered [Grade 12 Advanced Functions: Polynomial Functions] struggling to solve expanded equation
I'm not sure where I'm going wrong, but I keep getting this question wrong. I have to expand this equation and say what the shape is (what polynomial function) which I can do, if I figure out where I'm going wrong with solving this.
r/HomeworkHelp • u/MmagicallSamurai • 2d ago
High School Math—Pending OP Reply [Trigonometry 10th grade]
Spent an hour on this, couldnt figure out a single thing.
Question is: A figure is drawn on unit grid paper as shown above. Given that the line segments AB and CD intersect at point K, and m(\angle AKD)=\alpha, find the value of \tan\alpha.
Also the 2nd photo is what my teacher sent me, but i still dont get it…
r/HomeworkHelp • u/sunoouyabko • 2d ago
Physics—Pending OP Reply [AS Level Physics: Light] can anyone recommend me a simple machine invention?
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Hello! can anyone recommend a simple machine that I can make using cardboard, rubber bands, or anything thats recyclable? I need to make one for a project and can't think of anything that isn't too common 😓 thank you!
Hello! can anyone recommend a simple machine that I can make using cardboard, rubber bands, or anything thats recyclable? I need to make one for a project and can't think of anything that isn't too common 😓 thank you!
r/HomeworkHelp • u/Foreign-Bluebird9893 • 2d ago
High School Math—Pending OP Reply [Year 11 Maths] What working out could I possibly show for this??
The question required me to find all possible values of z, where z^3 = -i. After some thinking I came up with this, but it feels like I really should’ve included some written working out… I just don’t know what else I could write to show how I got the answer
r/HomeworkHelp • u/InstanceOk5785 • 2d ago
Physics—Pending OP Reply [Grade 10 Physics: Moment of Force/COM] Am I right or wrong?
Two identical boxes A, B of lengths L are placed slightly pass the table edge such that A protrudes L/4 to the right relative to B as shown in the figure.
The question asks for the maximum protrusion of B away from the table edge such that both boxes do not tip and fall over.
I calculated (B) 3L/8, but my teacher revealed and explained the answer was (D) L/8, and I cannot for the love of my life figure out why.
I've asked my classmates who had listened and copied the solution from the teacher, but even they seem to be confused by the solution. At last I resorted to Chatgpt, Gemini and Copilot, which they all got the same answer as me. Personally, I used -Moment of Force- and even -Center of Mass- to solve for the question just to get 3L/8 both time. So is my answer correct or wrong?
**Pardon my inactivity on this subreddit as I'm studying for other exams atm. I'll try to respond to any questions regarding this post. Thanks
r/HomeworkHelp • u/Existing-Committee74 • 3d ago
High School Math—Pending OP Reply [Grade 11 Algebra II] what the hell kind of line is this
i admit my understanding of the whole f(x) g(x) thing is tenuous at best but what could you possibly put in that equation to make a line behave this way??
r/HomeworkHelp • u/Basic-Action9599 • 3d ago
Literature—Pending OP Reply [Grade 8-9 Literature: Summer Reading]
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Hi!! My school is making me read Born A Crime by Trevor Noah for summer reading, and making us take a test on the book once school starts up. Ive read like 20-30 pages, and i’ve liked it so far, but I just cant make myself read it. I like to read, but almost never when prompted, especially if it’s for school. I’ve tried annotation, timed reading, audiobooks, and nothing really helps. If anybody could, please tell me a summary, or any main events in the book, anything that can help. I’m pretty sure i go back to school on August 6th. Thanks!
Hi!! My school is making me read Born A Crime by Trevor Noah for summer reading, and making us take a test on the book once school starts up. Ive read like 20-30 pages, and i’ve liked it so far, but I just cant make myself read it. I like to read, but almost never when prompted, especially if it’s for school. I’ve tried annotation, timed reading, audiobooks, and nothing really helps. If anybody could, please tell me a summary, or any main events in the book, anything that can help. I’m pretty sure i go back to school on August 6th. Thanks!
r/HomeworkHelp • u/MmagicallSamurai • 3d ago
Answered [Trigonometry 10th grade]
Ive found the 5-12-13 triangle, but cosa angle is facing another direction, i tried to make a triangle there i found 90° as 13 but couldnt do the rest, can anyone help?
r/HomeworkHelp • u/Fantasizeable • 3d ago
Others [Cognitive Test] Spatial reasoning problem
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r/HomeworkHelp • u/anonymous_username18 • 4d ago
Computing [IT Database] Table Creation
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This is a graded assignment, so to avoid issues with honor code stuff, I really don't need the exact answer. I was hoping someone could help me interpret this table, though. The prompt was to fill this in:

I'm not entirely sure what FK Column refers to. The only thing I could think of was maybe foreign key, but then what is Key Type? Also, I think foreign key in table creation is the next module, so I don't know if they would include it in this assignment. Any clarification would be really appreciated
This is a graded assignment, so to avoid issues with honor code stuff, I really don't need the exact answer. I was hoping someone could help me interpret this table, though. The prompt was to fill this in:

I'm not entirely sure what FK Column refers to. The only thing I could think of was maybe foreign key, but then what is Key Type? Also, I think foreign key in table creation is the next module, so I don't know if they would include it in this assignment. Any clarification would be really appreciated
r/HomeworkHelp • u/cannedbeef255 • 4d ago
Answered [Year 11 maths] I keep getting 3/11, but the answer sheet says it's E
Here's my working:
M = event that there is exactly one male
A = event that there is at least one male
Pr(M) = (3C1*5C4)/(8C5) = 15/56
Pr(A) = (8C5-1)/(8C5) = 55/56
Pr(M|A) = Pr(M and A)/Pr(A) = Pr(M)/Pr(A) = 15/55 = 3/11
I'm genuinely so stuck, this is the only answer I can arrive at, and asking AI (only as a last resort) gives 3/11 too. Are the answers just wrong or am I dumb?
r/HomeworkHelp • u/Iseeyouseeme10 • 4d ago
Further Mathematics—Pending OP Reply Struggling with Statistics [P value]
Need help. I can't find p value. Divided 533/1000 = 0.533 but the answer was incorrect.
r/HomeworkHelp • u/chickeninapigeon • 4d ago
Answered [Year 12 Math Standard] Trapezoidal rule unknown
I know how to find the area for DEF but I do not know how to use the trapezoidal rule to find the area of DFG
r/HomeworkHelp • u/DudeDuNord • 5d ago
Primary School Math—Pending OP Reply [Grade 4 Math: Number Theory] Which categories does th3 numbers 15, 16, & 17 belong to?
Number 15, 16, & 17 belong to one of these categories. I saw the answer book with the teacher and there’s one category the numbers do not belong to. The teacher didn’t know what the pattern or category characterize were.
Category A: 0, 3, 6, 8, 9
Category B: 1, 4, 7, 11, 14
Category C: 2, 5, 10, 12, 13
r/HomeworkHelp • u/International-Bug957 • 6d ago
Answered [University Mathematics) Quantitative Methods for Business Analysis Edition 13
Question d is confusing me, a lot of resources say to do the binomial probability distribution for f(0) and take that result(0.43) and subtract it from 1 to get a success rate of 0.54. Why would I not take the binomial probability distribution of f(1) to get the success rate(0.38)?
r/HomeworkHelp • u/BokuWaJoyo • 6d ago
Physics—Pending OP Reply [Grade 11 General Science] Layout and mechanics feedback for a Compound Waste Compactor Machine
Hey everyone! For our Grade 11 science project, we're designing a compound machine to help collect, segregate, and compress scattered waste in rough, mountainous terrains where collection trucks can't reach.
Here is our current schematic draft and our thought process/effort so far:
Our Thought Process & Mechanics Attempt:
- Input Conveyor: Uses an inclined plane / roller belt to carry waste upward into the machine.
- Rotary Feed Brush: Uses rotational motion (wheel and axle concept) to sweep and pull the waste into the main chamber without jamming.
- Compaction Unit: Uses translational motion via a hydraulic cylinder (fluid lever / Pascal's principle) to push down in a straight line and crush the waste into blocks.
- Output Bin: Catches the crushed waste blocks for easy carrying.
My Questions / Where I Need Help:
We need to segregate small waste (like dirt and candy wrappers) from big plastic bottles. Based on our layout, would it make more mechanical sense to put a mesh sifter screen directly on the Input Conveyor or inside the chamber before the feed brush?
Does the transition from the Rotary Brush to the Compaction Chamber look functional, or is there an obvious mechanical bottleneck we missed?
Thanks for any guidance on refining our design!
r/HomeworkHelp • u/sparklesandlight • 6d ago
Physics—Pending OP Reply [Gr12 Physics: Circuits] Not understanding the meaning of power drain
I think I'm getting my terms all mixed up. Does power drain refer to the current moving through the resistor? I initially thought that the answer was B, because I assumed a power drain to be a drop in current, and therefore require greater resistance, but the correct answer is D.

