This table gives information about how far hiker walks during the times indicated. Use the data to answer the question. What was the hiker’s average speed for the entire hike?
A.) 2.0 km/h
B.) 6.7 km/h
C.) 5.7 km/h
D.) 10 km/h

solution:

the given function is ,

      =

the three roots of this quadratic function is , 0 ,8 and 10.all the roots are real and rational.

if a quadratic equation is of the form ,

sum of the roots = a + b +c= 0+8+10=18=  

product of roots taken two at a time = a b + b c+ c a = 0+80+0=80 =  

product of roots = a b c = 0=  

there are 11 doors in a hall starting from 0 to 11.the entry in the hall is permitted through gate number 0 and exit is allowed through only gate number 8 and 10.so, three roots(0,8,10) of quadratic function is given by entry and exit route of this hall.

table 3 represents a direct variation function. : )