Please explain and show the steps of the following questions. Thank you!

The figure above shows the level curves of a function f(x, y) around a maximum or minimum, M. One of the points P and Q has coordinates (X1, y1 ) and the other has coordinates (x2, y2). Suppose b > 0 and c > 0. Consider the two linear approximations to f given by f (x, y ) ~ a + b(x - x1) + c(y-y1) f ( x, y) ~ k + m(x - x2) + n(y - y2). (a) What is the relationship between the values of a and k? a = k V (b) What are the coordinates of P? ( x2 V y2 v (c) Is M a maximum or a minimum? minimum (d) What can you say about the sign of the constants m and n? m 0 v