\fFind the directions in which the function increases and decreases most rapidly at Po. Then find the derivatives of the function in these directions. f(x,y, z) = (x/y)-yz, Po(2, 1, - 3) . . . The direction in which the given function f(x,y,z) = (x /y) - yz increases most rapidly at Po (2, 1, - 3) is u = ]i+ (Dj + ([ DK. (Type exact answers, using radicals as needed.) The direction in which the given function f(x,y,z) = (x / y) - yz decreases most rapidly at Po (2, 1, - 3) is v = i+ (Jj+( )k. (Type exact answers, using radicals as needed.) his The derivative of the given function f(x,y,z) = (x / y) - yz in the direction in which the function increases most rapidly at Po (2, 1, - 3) is Duf=] (Type an exact answer, using radicals as needed.) The derivative of the given function f(x,y,z) = (x/ y) - yz in the direction in which the function decreases most rapidly at Po (2, 1, - 3) is Dyf = (Type an exact answer, using radicals as needed.)