# Thread: Hello everyone!

1. ## Hello everyone!

Hello, My name is Martin, I'm from Czech republic. I study at High school. Math is my favourite subject. I hope I will learn something new at this forum :-)

PS: May I ask you for send me a link for using latex. I used latex for many years at Czech math forum but here I have no idea..

$x^2+3x+9=0$

$3x^2+x$

2. ## Re: Hello everyone!

Hi. Something on this page should help.

LaTeX Help

3. ## Re: Hello everyone!

Welcome to Math help Forum! Here LaTeX don't work if you type with in $__$ sign. All codes are same just type using TEX and /TEX

4. ## Re: Hello everyone!

just testing:

$\displaystyle -5x^2$

5. ## Re: Hello everyone!

just testing 2:
$\displaystyle 2sin^2x+cos^2x+sinxcosx=1$

$\displaystyle 2(1-cos^2x)+cos^2x+sinxcosx=1$

$\displaystyle 2-2cos^2x+cos^2x+sinxcosx=sin^2x+cos^2x$

$\displaystyle 2-cos^2x+sinxcosx=sin^2x+1-sin^2x$

$\displaystyle 2-(1-sin^2x)+sinxcosx=1$

$\displaystyle 2-1+sin^2x+sinxcosx=1$

$\displaystyle 1+sin^2(x)+sinxcosx=1$

$\displaystyle sin^2x+sinxcosx+0$

$\displaystyle sinx(sinx+cosx)=0$

1. CASE

$\displaystyle sinx=0$

$\displaystyle x=k*pi$

2. CASE

$\displaystyle sinx+cosx=0$

$\displaystyle \frac{sinx}{cosx}+1=0$

$\displaystyle \frac{sinx}{cosx}=-1$

$\displaystyle tanx=-1$

$\displaystyle x_1=pi/4+k*pi$
$\displaystyle x_2=3/4pi+k*pi$

6. ## Re: Hello everyone!

they'll appear the same but proper syntax is \sin x, \cos x, \tan x etc.

7. ## Re: Hello everyone!

thanks for answer, but have you found any mistakes please?

8. ## Re: Hello everyone!

I didn't check, I thought you were just testing the LaTex...

You've got some unnecessary steps but you get the correct answer in the end.

9. ## Re: Hello everyone!

That's great, i am so grateful for you. Have a nice day