Please help with practice questions 1 and 2.

1.

Let f (x, y) = tam6"). Find the equation for the tangent plane to the graph of f at the point (1, 2) . (Use symbolic notation and fractions where needed.) Let P be the tangent plane to the graph 0fg(x, y) = 20 10x2 20y2 at the point (4, 2, 220). Let f (x, y) = 2 2x2 yZ. Find the x-coordinate of the point on the graph of f where the tangent plane is parallel to P. :1