Testing for Exactness In Exercises 1-4, determine whether the differential equation is exact. Explain your reasoning.
\(x \sin y \ d x+x \cos y \ d y=0\)
x sin y dx+x cos y dy=0
Step 1 of 5) “The derivative of ƒ at P0 in the direction of u” The partial derivatives ƒx(x0 , y0) and ƒy(x0 , y0) are the directional derivatives of ƒ at P0 in the i and j directions. This observation can be seen by comparing Equation (1) to the definitions of the two partial derivatives given in Section 13.3.