 # Learn Indirect Proof with Plainmath's In-Depth Explanations and Real-World Examples

Recent questions in Indirect Proof jorgejasso85xvx 2022-11-19

## Suppose that $\mathcal{U}$ is the universal set, and that $A$, $B$ and $C$ are three arbitrary sets of elements of $U$. Prove that if $C\setminus A=B$, then the intersection of $A$ and $B$ is empty. Hint: use an indirect proof. piopiopioirp 2022-11-19

## Prove the following through an indirect proof-if $m+n$ is even, then $m$ and $n$ are even or $m$ and $n$ are odd. Barrett Osborn 2022-11-18

## Does proving that two lines are parallel require a postulate? Filloltarninsv9p 2022-11-15

## Discrete math: proofsFor any three integers $𝒙,𝒚$, and $𝒛$, if $𝒚$ is divisible by $𝒙$ and $𝒛$ is divisible by $𝒚$, then $𝒛$ is divisible by $𝒙$. Kameron Wang 2022-11-04

## Does ${x}^{2}\equiv 3$ (mod $q$) (where $q$ is an odd prime) have infinite solutions? Madison Costa 2022-11-02

## Use an indirect proof to show that if ${x}^{3}+x-1>10$ then $x>1$. Vincent Norman 2022-10-30

## Prove for all positive real numbers $x$ and $y$, if $x+y\le \left(4xy\right)/\left(x+y\right)$, then $x=y$ Maverick Avery 2022-10-28

## Prove the square root of $2$ is an irrational number. Paloma Sanford 2022-10-26

## Why are direct proofs often considered better than indirect proofs? Winston Todd 2022-10-16

## Let $a,b$ and $c$ be real numbers where $a>b$. Prove that if $ac\le bc$, then $c\le 0$. mafalexpicsak 2022-10-15

## What is the negation of " $A\subseteq B$ "? Aldo Ashley 2022-10-13

## How to prove a function has no local minima.?$f:{\mathbb{R}}^{2}\to \mathbb{R}$ , of class ${C}^{2}$ vagnhestagn 2022-10-08

## Let $G$be an acyclic graph with $c$ components. Show that the number of edges of $G$ is $n-c$. hikstac0 2022-10-07

## Suppose ${x}_{1},{x}_{2},{x}_{3}\in \mathbb{R}$. Prove that one of the ${x}_{i}$ must be greater than or equal to the average $\frac{1}{3}\left({x}_{1}+{x}_{2}+{x}_{3}\right)$. Charlie Conner 2022-10-06

## Prove that $\frac{2022}{n}+4n$ is a perfect square iff $\frac{2022}{n}-8n$ is a perfect square Sincere Garcia 2022-10-03

## If $\left(n+1{\right)}^{2}$ is even then $n$ is oddfind what proof works best with this question Diana Suarez 2022-09-27

## Is it possible to prove directly that even perfect squares have even square roots? Or, symbolically: Medenovgj 2022-09-26

## Let $Q\left(z\right)=\left(z-{\alpha }_{1}\right)\cdots \left(z-{\alpha }_{n}\right)$ be a polynomial of degree $>1$ with distinct roots outside the real line.We have$\sum _{j=1}^{n}\frac{1}{{Q}^{\prime }\left({\alpha }_{j}\right)}=0.$Do we have a proof relying on rudimentary techniques? Melina Barber 2022-09-25 gemauert79 2022-09-24