Verify that Laplace’s equation in 2D polar coordinates(r, ??), where x = r cos??, y = rsin??, is...

Verify that Laplace’s equation in 2D polar coordinates(r, 𝜑), where x = r cos𝜑, y = rsin𝜑, is 𝜕2u 𝜕r2 + 1 r 𝜕u 𝜕r + 1 r2 𝜕2u 𝜕𝜑2 = 0 Show that that the sum of the first two terms can be written 1 r 𝜕 𝜕r ( r 𝜕u 𝜕r )