On mars, if you hit a baseball, the height f the ball a time t would be modeled by the quadratic function h(t) += -1.85t^2+20t+1 is in seconds and h(t) is in meters a) when will the ball hit the ground?
b) how long will the ball be above 17m?

The ball will hit the ground when h(t)=0 so

-1.85t^2+20t+1=0  using the quadratic formula for simplicity...

t=(-20±√407.4)/-3.7, since t>0

t=(-20-√407.4)/-3.7 seconds

t≈10.86 seconds  (to nearest hundredth of a second)



How long will the ball be greater than 17m, h(t)>17

-1.85t^2+20t+1>17

-1.85t^2+20t-16>0

t>(-20+√281.6)/-3.7

t<(-20-√281.6)/-3.7   approximately...

t<9.94

t>0.87

0.87<t<9.94  to the nearest hundredth of a second

0.88≤t≤9.93

9.93-0.88=9.05 

So the ball will be greater than 17m for about 9.05 seconds.

Not sure what the question is but i hope this x = years100 * x