Question

f(x, y) = sin(x).cos(y) Which of the following is a critical point?

(a) (^Π⁄4, ^Π⁄4)

(b) (- ^Π⁄4, ^Π⁄4)

(c) (0, ^Π⁄2)

(d) (0, 0)

I had been asked this question in semester exam.

My question is based upon Maxima and Minima of Two Variables topic in section Maxima and Minima of Engineering Mathematics

Answer 1

The correct option is (c) (0, ^Π⁄2)

To elaborate: fx = cos(x).cos(y) = 0

fy = – sin(x).sin(y)

→(x, y) = (0, ^Π⁄2).