given the expression
[tex]15=0.5t^2-5.6t+25.2[/tex]
where
P= price
t=time
t(0)= year 2000
given the formula
[tex]x=-b\frac{\pm\sqrt{b^2-4ac}}{2a}[/tex]
where
a=5
b=-56
c=102
then
[tex]t=56\frac{\pm\sqrt{(56)^2-4(5)(102)}}{2(5)}[/tex][tex]t=56\frac{\pm2\sqrt{274}}{2*5}[/tex][tex]t=\frac{28\pm\sqrt{274}}{5}[/tex][tex]t1=\frac{28+\sqrt{274}}{5}=8.91[/tex][tex]t2=\frac{28-\sqrt{274}}{5}=2.289[/tex]
since t(0)=2000 years
then a time of
t1=8.91 represent the year 2008
t2= 2.28 represent the year 2002
