In y=kx+b, k determines whether it is positive or negative, positive means increase, negative means decrease, and b means the coordinate of this function on the y axis.

In y=k/x, k is decreasing and k is increasing negatively.

y=ax？ In +bx+c, a represents the opening direction, positive indicates upward, negative indicates downward, and x=-b/2a represents the symmetry axis; Positive: before x=-b/2a, it first decreases and then increases; Negative: x=-b/2a is increasing before and decreasing afterwards.

2.