???????????? vertex ???????????
y=-0.0003 x^2 +0.03x +1.3
me thank yu want point weer slope=0, wich is the hi point
yu hav negatix x^2, so parabols tern DOWN
dy/dx=-0.0006x +0.03
tu find horizontal tangent, set slope=0, so
x=-0.03 / 0.0006...=-3/0.06...=-300/6=-50
=50 yeers B4 the time span yu talk bout
me spekt the quashun NOT true for that yeer