Reddit » Math Help

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Reddit » Math Help

4h ago

My book is showing examples of inductive proofs. To prove that a factorial sequence is greater than an exponential sequence for all inputs i>4, first we assume proposition p sub (i-1) is true for any value
i > 4 in (i-1)! > 2i-1.
Then, to prove p sub i is true, we first multiply both sides by i:
i(i-1)! > i(2i-1).
This is where I get lost. My book simplifies that so all of the equations are:
i > 4
(i-1)! > 2i-1
i(i-1)! > i(2i-1)
i! > 5(2i-1)
i! > 2(2i-1)
i! > 2i
I understand why i(i-1)! = i! and why 2(2i-i) = 2i, but I can’t figure out where i! > 5(2i-1) or i ..read more

Reddit » Math Help

4h ago

right now, I'm studying Gilbert's 18.06sc lin_alg (pls chill, i have passed a pure mathematical linear algebra course last semester. I know the concepts algebraically)
I'm passed through the first 1/3 of the course, meaning i know the things below :
Elimination
Solving Ax=b
4 fundamental subspaces
inverse matrices
when solving the first exam, i came across this question :
https://preview.redd.it/91b5xlo5y0id1.png?width=752&format=png&auto=webp&s=dccffb513e6be40a613584115bd965430f9f8f8c
there's 3 things i don't understand here :
How does column 2 show the relationship between co ..read more

Reddit » Math Help

4h ago

Im studying math by myself due to my last school having a shitty math curriculum, basically cut the whole thing into thirds and trying to teach the first third.
I don't understand 3. step first equality and photomath just throws an error at me...
Heres the exercise
submitted by /u/frywarrior
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Reddit » Math Help

4h ago

Hello, Im currently trying to solve a linear system of equations for a while now. My solutions never make any sense at all. Im questioning myself wether im just making stupid little mistakes which i drag along or if i just missunderstood the whole process. Maybe someone could look over my last attempt and give me a little critique.
https://imgur.com/a/t9yyXZl
Im applying the Gauß algorithm with trying to zero one variable more for every equation by adding/subtracting multiples of another line. I have solved various others ones with some issues but i always got it to work in the end.
Thanks in ..read more

Reddit » Math Help

18h ago

I am doing a chapter in a textbook on laplace transforms and on last question there is what I imagine to be fractional decomposition however the people making the book have skipped their working out and gone straight to the decomposed answer which I can't seem to make.
https://imgur.com/a/lGBy5ue
I've tried adding the two fractions together then spliting them up into three different parts A/(s-2) + b(s+2) + Cs+D/s^2+4 and then solving. However, I get D to be -1/4 rather than -1/8. I am sure it is just a simple mistake since I haven't done partial fractions in ages. Any help would be great
su ..read more

Reddit » Math Help

2d ago

What topics in would I “need” to recover to prepare for Diff EQs and Linear Algebra? I literally forgot everything after the Summer.
submitted by /u/Nill479
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Reddit » Math Help

2d ago

I run a sports league and it's just me, so please double check my work:
All teams play each other 1 time. A match is 3 games, each game is to 11, a maximum of 33 points can be scored per match, any points scored after 11 (because you must win by 2) are scored as OT (overtime).
This was a small season, 4 matches played per team.
Team 1 =
Games: 10 wins, 2 losses (83% winrate)
Points: 121 won, 67 loss, OT=1 (64% winrate)
Team 2 =
Games: 10 wins, 2 losses (83% winrate)
Points: 126 won, 58 loss, OT=0 (68% winrate)
Based on points, Team 2 is the winner. When Team 1 vs Team 2, Team 1 won with the m ..read more

Reddit » Math Help

2d ago

The proof is pretty straightforward, I can do it myself, and I'll write it: For every x and every c > 0 within R, there exists a natural number N such that c*N > x. Proof: If x <=0, N=1 implies cN > x. So assume x > 0.
Then x / c is positive. By interspersing of integers by rationals, there is an N >= x/c. Multiplying by c, there is an Nc >= x. Set M to N+1 and we have Mc > x.
I just have trouble visualizing this for some reason. Sorry this question is so vague. It's like, I want to put this seemingly trivial proof (not just the result) in English but I can't. It's lik ..read more

Reddit » Math Help

2d ago

Picard lindelöfs proof is basically showing that the limiting function of a sequence of functions is a solution to a differential equation. However as im writing about this theorem my teacher wants me to prove how the sequence of functions converges. But, when i research about it online all the articles are just tooo complicated for me to understand as im still in high school. HELPppp pls
submitted by /u/crazypoetreader
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Reddit » Math Help

2d ago

Take base as 2 Log (x-3) + log(x-1) =3 .....(*) I.e. (x-1)(x-3)=8 X=5 or x=-1 We ignore -1 saying that number inside the log function cant be negative (as per https://youtu.be/LRbi_pMX1DM?si=5emsiEENPX4I5lQn at 36:45) . But if we take * as log (x-3)(x-1) or simply log (x2 -4x +3) , we can now use -1 as a solution. So why was -1 to be ignored
submitted by /u/Zealousideal_Bad3212
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