Sketch the graph of each function by finding the vertex or other methods like opens up/down or the y-intercept

What is the average rate of change for this function for the interval from x=2 to x=4 ?

Given that y varies directly to the square root of (x + 1), and that y = 1 when x = 8,(a)express y in terms of .x,(b)find the value of y when x = 3,(c)find the value of x when y = 5.

Find the distance between the pair of points a(-1,8) and b(-8,4)