the least common denominatore of 7 and 2 is 9
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.
the rocket cannot penetrate the ground, in a contextual sense, therefore the roots of this equation should be the domain of this function. i'll let you find the roots of this quadratic equation (hint: use the quadratic formula: