Agroup of three friend order a combo meal which includes two slices of pizza and a drink . each drink is priced at $2.50. if the combined total is $31.50, how much is the cost of a slice of pizza

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