1. S

    Solving an equation for a proof

    Hi all, I am reading a research paper and trying to understand an equation. I have tried it (I guess more or less) 10 times. But the result I am getting is completely different what author has achieved. $$ f(g) = e^{-K-g} \sum_{k=0}^\infty \frac{(Kg)^k}{(k!)^2} $$ Now I do not understand...

    More Inductive Proof Questions

    I want to have a little 'le cry'. Earlier today, I made a super detailed and tidy post on my question, but for some reason it didn't post(I think it was because of my internet), and now I've got to type it all again, and with less care and attention to detail. :( Anyways, not so long ago, I had...
  3. M

    Logic Proofs

    Hey guys these are the problems that I have a hard time doing. I get confused with how the laws work sometimes. If you guys could help me that would be awesome. Using the laws of sentential logic and the rules of inference prove the target formulas using the given WFFs: 1. Given (a → b) and...

    Confusion in Inductive Proofs

    Hey guys, I've been lurking around this site for a while, but I decided to finally stick in a question. Well, two, but I'll post one first and see if I can figure out the next one with the advice or help I get. I will post the question and then my working out and then what I'm confused about...
  5. M


    Hi I'm marsandfruit and I am a college student who's taking a cumbersome Philosophy course if anyone has any knowledge on how to do proofs using the Inference Rules and the Laws of Sentential Logic that would be wonderful.
  6. T

    Help with the formal proofs related to induction

    Hey everyone, I was wondering if someone can show me formal proofs to this exsercises. I got stuck and I really don't know how to write a formal proof of this. So if someone can help with this I'd be greatful! Thanks :)
  7. S

    Help with approaching proofs under exam conditions

    Hi, This could be a bit late, but I've got an upcoming exam this Friday. While preparing for it, I found that past exams often had one or two difficult linear algebra proofs. For instance: If Q is an orthogonal symmetric matrix, and \lambda is an eigenvalue of Q, then show that \lambda = \pm 1...
  8. C

    Geometry Proofs?

    I'm trying to do this for homework. Thanks. THE QUESTION
  9. C

    Help with Proofs

    I'm doing test corrections and I don't understand what is supposed to go in number 20. Any explanation would be helpful, thanks! THE QUESTION
  10. K

    Understanding Set Proofs

    No need in solving the problem, although I wouldn't mind, but I need some help understanding the symbols and such. I have this. A ⊆ B ^ A ⊆ C => A = ∅v (B ∩ C =! ∅) (same as picture) I understand the first half, but not the second. What does => mean? And what am I supposed to do with...
  11. C

    Help with Proofs

    I don't understand all the properties and how to get there I need someone to help me with my homework and please explain so I can understand. Thanks in advance! THE QUESTION
  12. T

    How do people start with proofs?

    I am taking my first college class (calc c) and the teacher gives us proofs as hw problems. I'm not really sure how to even start proofs. For example, one questions asks "If the terms of one sequence appears in another sequence in their given order, we call the first sequence a subsequence of...
  13. A

    Please help with easy geometry proofs.

    Hi. I need help checking these proofs. I already did some of it and tried, but I don't really get it. - Given: <2 is supplementary to <3 Prove: <1 is congruent to <4 - Given: Line AC is perpendicular to ray BE, and ray BE bisects <DBF Prove: <1 is congruent to <4 Please help!?!
  14. P

    Difficult Proofs I Cannot Find

    Hi, I cannot solve the following, could you please help me ? It is very urgent ! 1) Prove that : ∛ 5 + √2 is an irrational number 2) Prove that : ∛(45+29√2) + ∛(45-29√2) is an integer. Thanks for any help :) !
  15. S

    Prove x² + y² = 0 implies (x = 0 and y = 0)

    I am facing difficulty understanding the proof of this problem. It is my understanding that the only way that x2 + y2 can equal zero is if x = 0 and y = 0. Thus I would say that a sufficient proof would be that if the square of a real, non-zero number is positive than if either x > 0 or y > 0...
  16. U

    Two proofs that I'm unsure about

    I'm confused as to how proofs work. It's easy enough to show a counter example to prove false but if the statement is true it makes logical sense in my head but I can't put it into math on a sheet of paper. I'm not sure how to use all the symbols on the website so I'll write it out in plain...
  17. T

    Trigonometry Proofs

    Imgur I'm really bad at trig proofs, so if someone could show me the steps, or tell me what identities to use and lead me in the right direction, that would be appreciated.
  18. R

    Direct and Indirect Proofs

    What is the basic difference between direct and indirect geometric proofs as taught at the high school level using the statement versus reason chart?
  19. R

    Geometric Proofs Disappearing

    Why are more and more high schools across the USA doing away with direct and indirect geometric proofs? Why do students struggle so much with proofs?
  20. P

    further proofs

    We know that we can prove that: 0<AB\Longrightarrow (0<A\wedge 0<B)\vee (A<0\wedge B<0) But can we further prove that:0< AB\Longrightarrow (0\leq A\wedge 0\leq B)\vee (A\leq 0\wedge B\leq0) Or even further ,can we prove :0\leq AB\Longrightarrow (0\leq A\wedge 0\leq B)\vee (A\leq 0\wedge B\leq...