Whats the capacity of a childs juice box

Acircle has a circumference of 28.36 units what is the diameter of the circle

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

Can someone me with this graph problem by the way i need to know the answers by today since this assignment is due ! !