Index Notation - Quick one-line working

I was reading my lecturer's notes on GR where I came across the geodesic equation for four-velocity. There is a line which read:



Summing them up,

[tex]\partial_i g_{aj} u^i u^j - \frac{1}{2} \partial_a g_{ij} u^i u^j = \frac{1}{2} u^i u^j \partial_a g_{ij} [/tex]



I'm trying to...



Index Notation - Quick one-line working

Index Notation - Quick one-line working