Please help me with this! <3

How to determine whether two known pairs of points are on the same line.

Ineed ! the person who answers and shows their work on they got the answer first will be marked the !

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