Wikipedia:Reference desk/Archives/Mathematics/2008 August 24#Math question

There's a quarter-circle ABC with centre O and radius unit 1. There is a point D which is the midpoint of OC and DB is parallel to OA.

Ive tried to draw it roughly using characters cos i wasnt bothered to draw and upload a proper picture but it should give you a good idea of it.

A |\\\

| \\ B

| / \\

| / |

| / | \\

| / | \\

| / | \\

|____________________

O D C

I have been asked to "BY considering separately the triangle OBD and the sector OAB, show that the area of the shaded region OABD is 1/24(2π + 3 sqrt(3) )"

I get sqrt(3)/8 for OBD and 1/12π for OAB. And cant get to the required answer. What am I doing wrong?

By the way, this is not homework, Im just doing questions as part of my revision for my resits. --212.120.246.239 (talk) 17:19, 24 August 2008 (UTC)

:Your answer is equal to the given answer. What's the problem? Algebraist 17:25, 24 August 2008 (UTC)

OK, let's try it:

: $\{1\; \backslash over\; 24\}\backslash left(\; 2\backslash pi\; +\; 3\backslash sqrt\{3\}\backslash right)$

= \left({1 \over 24}\cdot 2\pi\right) + \left({1 \over 24}\cdot 3\sqrt{3} \right) = {2\pi \over 2 \cdot 12} + {3\sqrt{3} \over 3\cdot 8}

In the first fraction the "2"s cancel and in the second fraction the "3"s cancel. You get

: $\{\backslash pi\; \backslash over\; 12\}\; +\; \{\backslash sqrt\{3\}\; \backslash over\; 8\},$

the same thing you say you got. Michael Hardy (talk) 17:55, 24 August 2008 (UTC)

The name of the Greek mathemetician please —Preceding unsigned comment added by 84.45.143.243 (talk) 22:22, 24 August 2008 (UTC)

:There have been a number of Greek mathematicians, including these guys and these guys. Algebraist 22:27, 24 August 2008 (UTC)

::Perhaps after browsing Algebraist's suggestions, this or this or even this may be of interest. --hydnjo talk 23:30, 24 August 2008 (UTC)