$\nabla$ × P, where P is a vector, is equal to
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Px $\nabla$ x P − $\nabla^2$P
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$\nabla^2$P + $\nabla$($\nabla$.P)
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$\nabla^2$P + $\nabla$x P
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$\nabla$($\nabla$.P) - $\nabla^2$P
D
Correct answer
Explanation
$\text{The vector Triple product is}
\\
A \times (B \times C) = B(A.C) - C(A.B)
\\
Thus \hspace{0.2cm} \nabla \times \nabla \times P = \nabla(\nabla .P) P(\nabla.\nabla) = \nabla(\nabla . P) - \nabla^2 P$