×

# An interesting thing everyone must know..

$$0.99999....=1$$! Why? It was proven in many methods, even though its logically unequal. Try the basic one, the same method as making infinitesimals to fraction. Assuming $$x=0.9999...$$. Then $$10x=9.9999...$$. Subtracting: $10x-x=9.9999...-0.9999...$ $9x=9$ $x=1$ Even though we clearly declare x as 0.999..., The end result is one.

Note by Ivander Jonathan
2 years, 8 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:

This is very interesting, but I don't sure how does it.!!

- 2 years, 8 months ago

We also know that $$\frac{1}{3} = 0.33333...$$. Multiplying both sides by $$3$$ gives: $$\frac{3}{3} = 0.99999...$$, or $$1=0.99999...$$.

- 2 years, 5 months ago