How do I enter a logarithm as an exponent?
\, (backslash + comma) gives a small space, \ (backslash + space) gives a medium space while \quad gives a large space.
Code:a \, b a \ b a \quad b$\displaystyle a\,b$
$\displaystyle a\ b$
$\displaystyle a\quad b$
The small space is particularly useful for formatting integrals:
Code:\int \sin x \, dx$\displaystyle \int\sin x\,dx$certainly looks neater than $\displaystyle \int\sin xdx.$