The graph represents the solution interval to which inequality?

Question

The graph represents the solution interval to which inequality?

−4.9t2+40t+4=20

−4.9t2+40t+4≤20

−4.9t2+40t+4>0

−4.9t2+40t+4≥20

Answer 1

-4.9t²+40t+4=2

applying the quadratic formula, move 2 over and set the equation equal to 0 to get

-4.9t² +40t+4-2=0 or simplified,

=-4.9t² + 40t + 2 =0 x₁=(-40)±√40²+39.2 x₁= (-40)±√1639.2 -40±40.487

=(-4.9) + 40t + 2= 0 2((-4.9) -9.8 -9.8

a=--4.9 b= 40 c= 2

x₁ =(-40) ¯±√40²-4(-4.9)(2) x₁=(-40)±√1600+39.2 x₁=0.487

2(-4.9) -9.8 -9.8 or - 0.05 first solution

second solution:

x₂=-40-40.487

-9.8

=--80.487

-9.8 divide and you get 8.218 so x₁=-0.05 and x₂= 80.487