Question

plz tell me what is increasing function and what is decreasing functions?

Answer 1

Let function is y= f(x)
increasing function = Y value increases when x value increases
decreasing function= Y value decreases when x value increases

Clear for you?

Answer 2

definition is "f is increasing on the interval (a,b) if for any
\[x_1,x_2 \in (a,b)\] if
\[x_1<x_2\] then
\[f(x_1)<f(x_2)\]

Answer 3

visually it means curve is rising as you read from left to right