14.5.31In what direction is the derivative of f(x, y)P(9,2) equal to zero?Select the correct choice below and, if necessary, fill in the answer box to complete your choice. A.uequalsnothing(Simplify your answer. Use a comma to separate answers as needed. Type your answer in terms of i and j.)B. There is no solution.

The table below shows the approximate masses of a dust particle and a grain of pollen. dust particle 0.000000778 g grain of pollen 0.00000000155 g the mass of a dust particle can be estimated and written in the form a × 10^b, where a = 8 and b = the mass of a grain of pollen can be estimated and written in the form a × 10^b, where a = 2 and b = based on the estimates, the mass of a dust particle is approximately blank times larger than the mass of a grain of pollen.