(a) Find the critical point of the function f(x, y) = (25x + 5y + In(]x + y\). C = Use the Second Derivative Test to determine whether it is A. a local minimum B. a local maximum C. test fails D. a...

Solve both questions

Extracted text: (a) Find the critical point of the function f(x, y) = (25x + 5y + In(]x + y\). C = Use the Second Derivative Test to determine whether it is A. a local minimum B. a local maximum C. test fails D. a saddle point (b) (1)' + (?)° 2 If C is the part of the circle = 1 in the first quadrant, find the following line integral with respect to arc length. (7x – 3y)ds =