the discriminant tells how many solutions and what type
b^2-4ac is that disccriminant
where you have ax^2+bx+c=0
a=3
b=-5
c=4
discriminant=(-5)^2-4(3)(4)=25-somethingbiggerthan25=negative
since it is negative, you will have 0 real solutions and 2 complex solutions (if you remember quadratic formula, the discriminat is under sqrt sign so if it is negative you get complex roots)
18. 0 real roots
19. hit the ground means height=0
set to zero and solve
0=-16t^2+25t+3
use quadratic fomrula
for equaiton ax^2+bx+c=0
x=

a=-16
b=25
c=3
x=

x=

x=

apxos
x=1.79161 or -26.7916
since x=time, we can't have negative time so
it take 1.79161 seconds
20.
t=1
sub1 for every t
h(1)=-16(1)^2+25(1)+3
h(1)=-16+25+3
h(1)=12
12 feet
18. zero real roots
19. t=1.79161 seconds
20. 12 feet