1. The problem statement, all variables and given/known data The Laplace operator Δ is defined by: Δ= Show in polar coordinates r and Θ, that the Laplace operator takes the following form: http://upload.wikimedia.org/wikipedia/en/math/0/7/a/07a878276cffd0c680f3f827204aba24.png 2. Relevant equations x=rcos(Θ), y=rsin(Θ), r ≥ 0, Θ ∈ [0,2∏] 3. The attempt at a solution It seems simple; convert the x and y in terms of polar coordinates, and differentiate twice. However, when i attempt to differentiate twice, in respect to r and theta, my r disappears and the trig function simply reverts.