A lake contains brown trout and rainbow trout. A naturalist caught and released fish in the lake. She caught 6 brown and 9 rainbow trout. She estimates that there are 450 trout in the lake. If the naturalist's sample represents the lake's population, how many of the estimated 450 trout in the lake are rainbow trout?

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.

d. 145*2 is 290 than the total angle is 360 then minus 290 then divide by two