Exercise A: Patterns --Finding Formulas and Missing Values 1.
Andre selts silicon cell phone covers at his stall. His fixed cost is R500 per month and he
pays R25 per cell phone cover. His costs are shown in the table below:
Number of items (n)
144 4
2 3 10
Total cost in Rand (0) 500 525 550 575
875
(a) Find the formula for calculating his total cost. Use C for total cost and n for the
number of cell phone covers.
(b) Hence, calculate the values of the unknown letters. Show all your steps.
0
1
В
A​

(-1,-0.5)

step-by-step explanation:

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.