Ill give 30 if mary pitches a ball with the initial height of 8 feet and a velocity of 80 feet persecond how long will it take for the ball to hit the ground

Find the directions in which the function increases and decreases most rapidly at upper p 0p0. then find the derivatives of the function in these directions. f(x,y)equals=x squared plus xy plus y squaredx2+xy+y2, upper p 0p0left parenthesis 1 comma negative 4 right parenthesis