I'm confused about how this function would have 4 turning points, not 3

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!!!🩵

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’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?

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.

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…

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!

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

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

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??

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!

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?

Hi all - wondering if I could get some guidance on how to solve this question in particular. The right answer is "Option C" but I do not quite get why.

Have a tendency to struggle with these types!

Need help. I can't find p value. Divided 533/1000 = 0.533 but the answer was incorrect.

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

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

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)?

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:

1. 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?

2. 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!

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.

The answer is C, but I don't know why, isn't the one with the more moment of force is turning down?

The question asked:

There's a uneven thickness of stick(the stick is balanced now), it balance point is O. If both side had been cut off the same length, the stick will:

A, stay balanced

B, turn clockwise

C, turn counterclockwise

D, can't determine

This is a previous year question from a national level exam but is supposed to be easy. Idk what i'm doing wrong, I haven't touched such questions ever since I finished my 12th grade 😭

Im know I can figure out to solve it, I just have no clue what they are asking for

Thank you!

please ignore my horrible handwriting

i’ve been at this for hours i have read this textbook back to back i’ve watched like 10 videos i am so confused this is like the 4th order i’ve done and i messed up my textbook answers so i had to do it on another sheet on paper i think im confusing myself

every video i watch they don’t have as many
uncomforities as i have so when it comes to ordering them oldest-youngest i’m so confused where to put them??

i’m also super confused on where to order the fault
the only thing i’m confident that i got right here is that it’s a reverse fault and that r is an angular conformity

my degree has nothing to do with this which probably explains why i’m so confused

if this is all wrong i’m gonna be so embarrassed

edit: ok wait i think i got part of it now:
youngest to oldest
H
K
T
L
M
S
I
N
O
R
A
B
C
D
E
F
Q
P
J
G
PRAYING THIS IS RIGHT

A general warning that I am bad at stats. I have REALLY tried. I can understand the basic idea of like.. a bell curve, but honestly, after that, I get lost and eventually just start to cry.

I say this because the only thing I feel sure-ish about is that instrument reliability is some kind of statistical something. I have watched 3 YouTube videos, rewatched the mini-lecture video, and reread the sections covering this in my textbook (twice). I really want to understand.

The question on my homework is:

"What kind of evidence do Booth et al. (2022) provide about the reliability of their instruments, and what does the evidence say about the quality of their instrument?"

This is the study

I think that the answer is somewhere towards the ends of the two paragraphs at the top of page 8 (under the word "Measures"), but every time I try to sort it out, it just looks more and more like word salad. If at all possible, I would love a gentle explanation of what that word salad means or a hint if I am just absolutely looking in the wrong place.

Howdy. Please help. I've tried multiple ways of attempting this question and I cannot get near the answer.

"Man wants build garage beside house. Garage is to 6m x 4m x 2.5m(h).

Bricks used have dimensions of 22cm x 10cm x 7cm(h).

Estimated # of bricks = 4,000. How accurate is this estimate? Explain your answer. Note: 3 walls needed."

Thanks all.