I'm currently studying Discrete Mathematics right now on my own. These proofs are a good summary of what I've been doing. Right now I'm working through the How To Prove It Book by Daniel J. Velleman. I find your channel to be very helpful. Thank you for your videos!👋
In the first example of proof by contradiction, "If a is rational and ab is irrational, then b is irrational" Isn't starting with the assumption b is rational and coming to the conclusion ab is rational instead of irrational, same as proof by contrapositive? a is rational and ab is irrational -> b is irrational (P -> Q) b is rational -> a is rational and ab is rational (NOT Q -> NOT P)
good video but Im ngl idk how you proved these, If you could show your answer actually works that would be great. For a^2 not divisible by 4, if you could show how your final proof actually proves it is then that would be great.
Respect from Kazakhstan, I am a freshman at Kazakh-British Technical University, and you help me a lot with your videos about discrete mathematics ❤
Same thoughts!
I am from KBTU too, прикольно видеть что пол КБТУ на этом канале сидит))
Love your countries music!
What convenient timing!
My discrete math final is literally tomorrow!
@@minemanfan409 I always come back to this video before every exam😭
How is it going👀??
well mine is in 4 hours! uh oh
I'm currently studying Discrete Mathematics right now on my own. These proofs are a good summary of what I've been doing. Right now I'm working through the How To Prove It Book by Daniel J. Velleman. I find your channel to be very helpful. Thank you for your videos!👋
you just saved me a lot of time. Thanks mate!
This was great review before an exam THANK YOU
Convenient! My discrete math final is in 4 days :O.
How did you do
How did you do²(:?
YOOOOOO. Timing impeccable.
some of your proofs are too hard to follow man, too many shortcuts for mere mortals
This is good review, but it would be good to have a video where you explain each assumption, operation, or each intermediate steps you skipped.
This is more a remainder video.
Binge watching your videos before my Discrete math final in 4 days. Hopefully she goes fine.
In the first example of proof by contradiction, "If a is rational and ab is irrational, then b is irrational"
Isn't starting with the assumption b is rational and coming to the conclusion ab is rational instead of irrational, same as proof by contrapositive?
a is rational and ab is irrational -> b is irrational (P -> Q)
b is rational -> a is rational and ab is rational (NOT Q -> NOT P)
No
Yeah, another banger
thanks man!
Would an If and only if case require a proof by contrapositive and a direct proof?
You’ll be proving both P -> Q and Q -> P so you yes could do it with a direct proof and one by contra position.
thank you
still kind of confused. How do you assume or find what to find? And for question 2 I still don't understand why root x
Hi john!
7:07 I’m confused that question says “show that for x and y are positive numbers..” but you wrote “x - y = 0”?
Hello! In that same problem, it says that x
Look at this guy, it's like he has a timer for these things.
thanks man
Amazing. So much easier to understand than my foreign professor can't speak English properly
should it be: x= 2a for ALL a € Z?
isn't base case for last example n = 1?
why k+k greater than k+1
@@kurapikaff5770 wondering too
Assume k=2 then
K+k= putting the value of k
2+2=4
And
K+1=putting the value of k
2+1=3
Hence k+k > k+1
good video but Im ngl idk how you proved these, If you could show your answer actually works that would be great. For a^2 not divisible by 4, if you could show how your final proof actually proves it is then that would be great.
Why the FUCK I am learning this as a cs student
for complexity and formal languages :)
@@Trevtutor your response is like the explanation in the video
Same😢
At the last one, why can we say 2^k*2>2k? why can't it be just 2^k*2>k
because of the *2, it'd technically still be right but to keep the scale consistent, you multiple the k by 2 as well
In last example I can't see why you just stated that k>1