Problems with the Latex equation ecitor

I am trying to write 1 over 2. This should be easy as{1}{2} or by using the pull down "a over b" from the top of the display. It just does not work . What I end up with is 1- and a very small 2 under the line. To be fair I did manage to get it to work once! but how I just don't know!

I have just discovered that this problem only exists on the third equation down. I was trying to write the three equations which connect velocity constant acceleration time and distance. James

You've mixing doxygen with LaTex

You should be typing:

\f[ \frac{1}{2} \f]

which will give you

v=u+at

v^2=U^2 +2as

s=ut+ 1over2 at^2

it is the third one which gives the problem when typed in this order. However if I put the third one first no problem!

Easy

v=u+at

\f[ v=u+at \f]

i.e.

v^2=u^2+2as

\f[ v^2=u^2+2as \f]

i.e.

s=ut+ 1/2 at^2

\f[ s=u t+ \frac{1}{2} a t^2 \f]