(r×∇).(r×∇)=r.∇×(r×∇)(adsbygoogle = window.adsbygoogle || []).push({});

now in index notation it is written as,

=x_{i}∂_{j}x_{i}∂_{j}-x_{i}∂_{j}x_{j}∂_{i}

but when I tried to prove it ,it just came out twice.can anyone tell how it is correct(given is the correct form).i really mean that i was getting four terms which gave twice of above after reshuffling so prove it.

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# Problem with index notation

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