Hi,

I am using Bookdown to publish my final project in PDF but I do not find the way to print bold letters inside equations. I am using \boldsymbol command. If I use Rmarkdown without Bookdown, \boldsymbol works properly, but not if publishing via Bookdown.

For example, for the equation `\boldsymbol y_k = \nabla f(\boldsymbol x_{k+1})-\nabla f(\boldsymbol x_k)`

, which should be printed in PDF like the first equation, is printed like the second one instead:

I have tried by explictly loading amsmath package and does not work either. Also by loading bm package and using \bm but it gives me a compilation error.

Thanks in advance to anyone who can help me.