Hi everyone. I am told to find the equation of the tangent plane to the surface x^2 + 2xy^2 -3z^3 = 6. I do not know how to approach this problem, and I was wondering if anyone would be kind enough to help. I know that for example if I had an equation z = x^2 + y^2, with a point P(x0,y0) and I was asked to find a tangent plane at that point, I would just do z = z0 + partialX(x0,y0) * (x-x0) + partialY(x0,y0) * (y-y0). I can solve these problems quickly. Piece of cake. However, I have the equation x^2 + 2xy^2 -3z^3 = 6, with the equation not being equal to a variable (like 'z' in the previously mentioned example in the preceding paragraph) but rather equal to a constant. I have been searching for some time on approaches on how to solve such a problem with an equation equaling a constant (6 in this case) and I have not been successful. Could anyone be kind enough to help me out? I would be very grateful to anyone who would. Thanks, and have a good day!