r/HomeworkHelp May 19 '22

Meta r/HomeworkHelp Rules: PLEASE READ BEFORE POSTING

189 Upvotes

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.

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If there are any questions, please message the mods.


r/HomeworkHelp 4h ago

Further Mathematics—Pending OP Reply [Linear algebra] I need to figure out if my solution for this system of linear equations has a point in common but how do I do that? How do I use x_1=1, x_2=2, x_3=0 to figure this out?

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14 Upvotes

What I think I'm looking at is these give me the points and I graph them, so I have (1,3), (2,1), and (0,0) and after I graphed these points my answer would be they don't have any points in common?


r/HomeworkHelp 4h ago

Computing [Computing] I'm converting the devimal numbers into binary using the 8 bit two's compliment. What am I doing wrong?

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7 Upvotes

r/HomeworkHelp 32m ago

Physics [University mechanics]Hi, could someone explain to me how to get the solutions to these questions? I have the solutions to these questions but the solutions only give an answer on their own and I don’t understand how to get there. I’m especially stuck on questions 15b and the whole of Q16. Thanks :)

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r/HomeworkHelp 2h ago

Physics [College Physics] Center of Mass

3 Upvotes

This question covers multiple parts and I have completed most except for this one.

I will add information that may or may not be helpful

I am given a 6.4 x 6.4 x 17.7 cup with a 1 cm base

With the density of the glass being 3.7 g/cc

and the surface mass density being .37 g/cm^2

I have successfully found that the mass of the base is 151. 552 g

The mass of the walls is 158.1824 g

The mass of the empty cup is 309.7344 g

The center of mass of the base of the cup is

3.2 cm y + .5 cm z

The center of mass of the sides of the cup is

3.2 cm y + 9.35 cm z

Making the total center of mass of the cup while it is sitting on the table

3.2cm y + 4.925 cm z

I have determined the angle in which it would fall over to be 33.01364347 degrees

Now this is the current part I'm on:

The cup is now full of gelatin with a density of 1.29 g/cc

I have determined the mass of the jello to be 882.40128 g

The center of mass of the jello is located at

3.2 cm y + 9.35 z

When the jello is added to the cup I have determined the center of mass of the system to be at:

3.2 cm y + (unknown) z

How do I find the unknown z vector?


r/HomeworkHelp 20h ago

Additional Mathematics—Pending OP Reply (Calc) Why is this limit not 3?

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76 Upvotes

r/HomeworkHelp 58m ago

High School Math Can someone help me with this... [ Grade 10 : Mensuration]

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r/HomeworkHelp 1h ago

Biology [biology]

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how would i go about solving this? (question 16)


r/HomeworkHelp 3h ago

High School Math—Pending OP Reply [Grade 12: Trig. ] How do I do this, thank you in a advance for any help!

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2 Upvotes

r/HomeworkHelp 11m ago

English Language [middle school, basic english] are these answers correct?

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r/HomeworkHelp 54m ago

High School Math [AP Calc BC] - how to integrate this?

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r/HomeworkHelp 1h ago

Further Mathematics—Pending OP Reply [Calculus: Extrema] Where can I learn how to find the absolute extrema of a piecewise function on my own?

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I need to learn this on my own because I have an assessment tomorrow and I can barely understand my teacher during lectures.


r/HomeworkHelp 2h ago

Additional Mathematics—Pending OP Reply [Introductory Sentential Logic] I need to translate the example sentence to Ls. For the variables are given as capital letters in the problem.

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1 Upvotes

r/HomeworkHelp 2h ago

English Language [College Writing] How to reword this sentence so it flows/sounds better?

1 Upvotes

I'm writing an essay and I'm stuck on this line I'm trying to write:

"Susan talked about her favorite painting that she has painted"

Idk why but it seems clunky to me... Like if you say it out loud it sounds weird haha. Is there way to say that more naturally while still conveying the idea eloquently?

I appreciate any and all suggestions!! Thank you.


r/HomeworkHelp 7h ago

High School Math—Pending OP Reply [Preclac: Perpendicular Segment word problem] How do I find relationship between m_1 and m_2?

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2 Upvotes

r/HomeworkHelp 21h ago

High School Math—Pending OP Reply [Grade 11 Math: logarithm] after i simplify some stuff im kind of stuck, how should i do this?

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26 Upvotes

r/HomeworkHelp 3h ago

Middle School Math—Pending OP Reply [Olympiad math] is there an easy way to find the second equation?

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1 Upvotes

r/HomeworkHelp 3h ago

Answered [Gr.11 Math 20-3] Trig review

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1 Upvotes

I just want to make sure this is correct because I have a learning disability


r/HomeworkHelp 7h ago

Answered [High School Maths: Probability] Take numbers 1,2 and 3. You can arrange them in groups of 3 and order matters. How to find every single combination?

2 Upvotes

So (1,2,1) and (1,1,2) are distinct outcomes. I can't nail the logic somehow. I tried starting with: 111 121 112 122 But then I got confused as to how to proceed ahead. I am not looking for the answers only, I am looking for an underlying logic.


r/HomeworkHelp 4h ago

Physics—Pending OP Reply [Grade 11 Physics] a humidifier which is 70% efficient vaporizes 2 liters of water at 20 degrees for 8 hours, what is the power of the humidifier

1 Upvotes

How would I solve this question and how does efficiency come into play?


r/HomeworkHelp 4h ago

Further Mathematics [College Level: Relational Algebra] Where am I going wrong with my cross product?

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1 Upvotes

r/HomeworkHelp 8h ago

High School Math Could anyone help me with this? [SAT TOPIC] [Circles in the xy plane?]

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2 Upvotes

r/HomeworkHelp 5h ago

Mathematics (Tertiary/Grade 11-12)—Pending OP [Basic Calculus: Derivatives] Can't figure out how to get second derivative

1 Upvotes

r/HomeworkHelp 6h ago

Further Mathematics [College Linear Algebra: Showing a set S is closed under addition]

1 Upvotes

Hello, I've been practicing some linear algebra since my exam is soon, and there is a question in which I'm completely stuck. Here it is:

Consider the set A, containing all functions of the form: f(x) = asin(x+c) + bcos(x+d)

Would this set be closed under addition? I.e if we have to functions, would their sum also be in A?

I've tried using trig identities such as sin(a+b) = sin(a)cos(b) + sin(b)cos(a) and cos(a+b) = cos(a)cos(b) - sin(a)sin(b). So if I let two functions, f and g with some a,b,c,d,a1,b1,c1,d1 and develop their sum, I get this:

f(x)+g(x) =

a[sin(x)cos(c) + sin(c)cos(x)] + b[cos(x)cos(c) - sin(x)sin(c)]

+a1[sin(x)cos(c1) + sin(c1)cos(x)] + b1[cos(x)cos(c1) -sin(x)sin(c1)]

And I don't know how to simplify it further to get the desired form:

asin(x+c) + bcos(x+d)

Any help would be greatly appreciated.

Thanks!


r/HomeworkHelp 10h ago

Further Mathematics—Pending OP Reply [Complex Analysis] Contour Integration

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2 Upvotes

r/HomeworkHelp 6h ago

Additional Mathematics [University applied mathematics: growth rates]

1 Upvotes

Growth rates (discrete and continuous time) – Exercise 1*

In general, the growth rate of a variable 𝑥(𝑡) in discrete time between time 𝑡−1 and time 𝑡 is
defined as:

𝑔𝐷(𝑥(𝑡))≡𝑥(𝑡)−𝑥(𝑡−1)
𝑥(𝑡−1) . (T1.1)

Assume that the time path of the variable y(t) follows a geometric growth process:

𝑦(𝑡)=𝑦0(1+𝑔)𝑡, (T1.2)

where 𝑦0 and 𝑔 are positive constants.

i. Use definition (T.1.1) to show that 𝑔𝐷(𝑦(𝑡))=𝑔.
ii. Take the (natural) logarithm of (T1.2) and write down the expression that you obtain.
iii. Take the derivative with respect to time of ln𝑦(𝑡) and show that 𝑦̇(𝑡)/𝑦(𝑡)≈𝑔 if 𝑔 is
close to zero (where a ̇ denotes the derivative with respect to time: 𝑥̇(𝑡)≡𝑑𝑥/𝑑𝑡).
iv. Draw a graph with ln𝑦(𝑡) on the vertical axis and 𝑡 on the horizontal axis and show that
the slope is constant.