# Clarification....

I am trying to answer this problem: https://brilliant.org/community-problem/primeprimeprime/?group=0jEjslvgEVDa

The answer should be 5. I think because p^2 is congruent to 1 modulo 4 (for p >= 3). From the equation: p^2 - 2q^2 = 1 and so... p^2 - 1 = 2q^2 .... 2q^2 is divisible by 4 and so q^2 is even and sqrt of q^2 must be even but no prime except 2 satisfies this...

P.S. Do you have any advice on how to solve level 4 or 5 problems?.... I sometimes (in despair) use trial and error method....

Note by John Ashley Capellan
4 years, 2 months ago

MarkdownAppears as
*italics* or _italics_ italics
**bold** or __bold__ bold
- bulleted- list
• bulleted
• list
1. numbered2. list
1. numbered
2. list
Note: you must add a full line of space before and after lists for them to show up correctly
paragraph 1paragraph 2

paragraph 1

paragraph 2

[example link](https://brilliant.org)example link
> This is a quote
This is a quote
    # I indented these lines
# 4 spaces, and now they show
# up as a code block.

print "hello world"
# I indented these lines
# 4 spaces, and now they show
# up as a code block.

print "hello world"
MathAppears as
Remember to wrap math in $$...$$ or $...$ to ensure proper formatting.
2 \times 3 $$2 \times 3$$
2^{34} $$2^{34}$$
a_{i-1} $$a_{i-1}$$
\frac{2}{3} $$\frac{2}{3}$$
\sqrt{2} $$\sqrt{2}$$
\sum_{i=1}^3 $$\sum_{i=1}^3$$
\sin \theta $$\sin \theta$$
\boxed{123} $$\boxed{123}$$

Sort by:

Thanks, I've updated the answer accordingly. Can you add a solution to it?

Staff - 4 years, 2 months ago