Question

The function i(t)=-0.1t^2 + 1.4t represents the yearly income (or loss) from a real estate investment where t is time in years. After what year does income begin to decline.

Answer 1

vertex if this parabola is \[\frac{-b}{2a}=\frac{1.4}{.2}=7\]

Answer 2

since the parabola faces down it increases and then decreases, so answer is after 7 years..

Answer 3

ok. thanks. medal.

Answer 4

welcome