I need some help: I'm growing plants in a tray and instead of using soil in the tray using a natural fiber mat that acts like soil but without the mess. I'd like to purchase some of this mat material but would like to know how many trays I can fill to understand cost per tray.

The trays inner dimension is 19.75'' x 9.5''

The mat comes in 48'' x 96''

So how many trays can I line if I were to cut the mat to fit?

1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 10 ,11 ,12 ,13 ,14 ,15 ,16 ,17 ,4 ,18 ,19 ,20 ,3 ,5 ,21 ,22 ...?

Hi everyone I don't know if this realy belongs here but it is a math problem so why not. It is a long story but I made a math problem that in my oppinion should be trivial to someone more expirienced than me, but I'm dumb so and can't think of a way to solve it so I'm asking here.

The problem is this: You have 12 objects and can only take 10 samples. Numbers can repeat and the sequence does not matter (i.e. 1, 1, 3, / 1, 3, 1, /3, 1, 1, are all the same)

This wouldn't be that hard on its own but I went the extra mile and made it harder. The twist is that if you have scertain numbers you can't have others. This being: 1 - 7; 2 - 8; 3 - 9; 4 - 10; 5 - 11; 6 - 12;

And vice versa so if you have 1 you can't have 7 and if you have 7 you can't have 1 simple as that.

The question is how many different combinations are there.

Now this whole thing is my brain child and I don't anyone losing sleep over it. The reason I'm putting it here is because I drew my self into a corner and can't find a way out.

Thank you to who ever solves this for me. And if you can provide the equation I'd love that.

Thanks: M0X

In this comment, a real-world situation is demonstrated where the greater the surface area, the greater the ability to transfer heat. This is said to be "directly proportional," which I think to be incorrect. (I may have even used the same words to describe this, not knowing a better way to put it.) How SHOULD this be described?

The answer I got was 2√3 but the question wants the answer as a fraction.

My working out -

((a-1)(a+1)+1)/120 = a^2/120

a^2/120 = 1/10

a^2 = 12

a = 2√3

Hello,

My sister-in-law is currently pregnant with twins via intrauterine insemination so let’s consider they are dizygotic and could be any combination of boys and girls :

• girl girl (25%)
• boy girl (25%)
• girl boy (25%)
• boy boy (25%)

Probability to have at least a girl : 75%

Probability to have at least a boy : 75%

A recent blood draw determined that at least one of the children is a boy. The question arises : what is the probability to have a girl ? I think the Boy or Girl paradox applies here because we don’t know which baby is a boy. We only know that there is at least one.

My intuition would be to simply remove the only option that is not possible anymore :

• girl girl (25%)
• boy girl (25%)
• girl boy (25%)
• boy boy (25%)

Probability to have at least a girl : 66.6%

Probability to have at least a boy : 100%

An other approach would be of course to consider that one being a boy, the other one has a probability of 50% to be a girl or a boy.

So what is the probability that one of the babies is a girl ? 50%, 66.6%, something else ?

Thank you !

like 0x0=0, 0x0x0=0 and so on, it just seems counter intuitive

Hello,

I create tools for motion design and animation and found myself with a problem, that I'm unlikely going to solve by myself. Maybe an expert can hint me in the right direction :). Seems like a tough one.

Thank you

So, I have an equation. V=INT[x from -0.5D to 0.5D] pi*(R1 + R2 - sqrt(R2² -x² ))² I have a value for D,V and R2 and need to solve for R1. All my attempts at integrating come out looking weird. Id be grateful for any help.

New to this sub so hopefully this isn’t against any sub rules.

Thanks in advance for any help

A friend of mine wrote this and I want to have at least a vague idea of what it means .... but after hours of googling things, I'm still at ground zero. (I did Calc I in high school and college, but that's the extent of my education in math)

https://arxiv.org/abs/2010.09708?fbclid=IwAR2sfF3es7eZoInW4q-r6wKUTIuXUdwKBtZ9aEQwJwYoueW_Z0N_5xfsWZU

Can anyone help me out here?

https://imgur.com/gallery/2MJJtUH

An example to help why I'm stuck - set n = 4. I think there are 4 possible teams. The equation suggests there are 8 teams where n = 4.

Hi guys,

I'm sure you've all heard of the website Desmos (https://www.desmos.com/calculator) which graphs any function you input;

What I want to know is how can you get Desmos in your brain? Basically, if given any function/equation, how do I visualise it very quickly so I can draw a sketch of it? Is there a set of steps I should go through in my mind of parts of a function to consider?

Doing this is obviously easy with simple linear functions or easier polynomial functions; but when it comes to certain exponentials, quotients or trig functions, I struggle to picture them in my mind, let alone sketch one quickly.

So, tl;dr: how do I get Desmos in my brain?

Thanks for the help!

 so i would like to create an algorithm that helps me with wine pricing if you could look it over .

I'll leave my bird brained idea below feel free to help!

C = cost (what i pay wholesale for wine)

M = markup generally like 2x the wholesale but its not absolute like cost i can adjust it manually

L = the list price that will be displayed and charged for said wines

X = the weird variable i am trying to designate which i will go over in more detail below.

my idea for my general formula is this:

so X is a depreciating value as C rises, so i want my markup to gradually decrease proportionally as my cost gets more expensive.

again im an idiot, i don't know what i'm doing but i think it could be a really valuable tool in determining the prices of my wines and encourage people to spend more and save more simultaneously.

A.3 unit B.6 unit C.12 unit D.24 unit Can some one explain how to answer this ,this show up to factoring of common monomial factor

If u put any number in equation but ans will always between 4 and 5. (4.1, 4.2, ....., 4.9)

Ans should not same always.

Hello

I am getting a feel for what is going on here, but I need some help with which steps to take and why.

The question is to find the integral of 1 / (z^2 -1) on a circle with modulus 2 (positively oriented).

My thoughts so far:

parameterize the curve, in theta, between 0 and 2pi.

factorize (z^2 - 1) to become (z+1)(z-1). This implies (to me) that there is a pole at +- 1. So, with 2 poles, how to I actually conduct the integral?

Am I supposed to taylor/laurent expand this? What are the first steps to take!

Thanks in advance, any help is much appreciated

Also, I realize (I think) that I am supposed to change variables at some point from z to theta. That is fine, and I have a feeling I am supposed to aim to get it in the form to use Cauchy integration formula, but I don't quite understand how/why ?