# Why is this not working?

• December 21st 2012, 02:01 PM
jakncoke
Why is this not working?
$f(x) = a_3 x^3$
results in an invalid equation error.
• December 21st 2012, 02:37 PM
fkf
Re: Why is this not working?
$f(x) = a_3 x^3$

I've had some problems with the TEXtags. I think on my computer the best way is to write the equation etc. and then mark the equation and press on the sigmabutton in advanced mode to wrap the equation with the TEXtags.
• December 22nd 2012, 12:13 AM
BobP
Re: Why is this not working?
Me too. Things that have worked earlier now producing a whole lot of invalid equations.