The equation y = -6t^2 + 51t describes the height (in feet) of a projectile launched from the surface of Mars at 51 feet per second. In how many seconds will the projectile first reach 100 feet in height?
100 = -6t^2 + 51t
-6t^2 + 51 t - 100 = 0 use Quadratic Fromula to find the values of 't' where the height = 100
the smaller 't' will be the first time the object hits 100 ft
a = -6 b = 51 c = -100
\(t = {-b \pm \sqrt{b^2-4ac} \over 2a}\)