1 radian?

How special is 1, in radians of course.

What's the significance of $\cos(1)?$ $\sin^{-1}(1)$ .

I've been wondering about these questions for the past few days. I even tried to derive $\sin(1)$ by calculus without a calculator, and I managed to get to $1=\sin^{-1}(1)+\sin^{-1}(p)$ where p is $\cos(1)$ , but you of course need a calculator from here.

So is there any significance to $\cos(1)$ and how would you derive it? (Without using a calc)

It also just crossed my mind, but what's significant about 1 radian in degrees?

#Geometry #Calculus #Trigonometry #Derivation #Easymoney

Easy Math Editor

This discussion board is a place to discuss our Daily Challenges and the math and science related to those challenges. Explanations are more than just a solution — they should explain the steps and thinking strategies that you used to obtain the solution. Comments should further the discussion of math and science.

When posting on Brilliant:

Use the emojis to react to an explanation, whether you're congratulating a job well done , or just really confused .
Ask specific questions about the challenge or the steps in somebody's explanation. Well-posed questions can add a lot to the discussion, but posting "I don't understand!" doesn't help anyone.
Try to contribute something new to the discussion, whether it is an extension, generalization or other idea related to the challenge.
Stay on topic — we're all here to learn more about math and science, not to hear about your favorite get-rich-quick scheme or current world events.

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

Math	Appears 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}`	$\boxed{123}$

Comments

You can derive sin(1) by using taylor series of sin function to any disired accuracy. Ofcourse sin(1) is transcendental hence it has no closed form in terms to square roots or n-th roots, and any finite sequence of basic operation on integers.

Hence I would like to conclude that there is nothing too significant for something like sin(1).

Ronak Agarwal - 6 years, 4 months ago

You can use linear approximation using derivative since a radian is very close to sixty degrees.

Sudeep Salgia - 6 years, 4 months ago

Math	Appears 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}`	$\boxed{123}$