Step-by-step explanation:
h(t) = -5t² + 20t + 18
this is a parabola (the curve an object follows when thrown up into the air and then falling back down).
and as such it will most likely have 2 solutions (one for when going up, and one for when falling back down again).
33 = -5t² + 20t + 18
15 = -5t² + 20t
-3 = t² - 4t
t² - 4t + 3 = 0
the solution of such a quadratic equation is
t = (-b ±sqrt(b² - 4ac))/(2a)
in our case
a = 1
b = -4
c = 3
t = (4 ±sqrt(16 - 4×1×3))/(2×1) = (4 ±sqrt(16-12))/2 =
= (4 ±sqrt(4))/2 = (4 ± 2)/2
t1 = (4+2)/2 = 6/2 = 3
t2 = (4-2)/2 = 2/2 = 1
the object reaches the height of 33 m first after 1 second (while going up), and then again after 3 seconds (while falling down again).
Answer:
Step-by-step explanation:
a
Answer:
angle C,D,A
Step-by-step explanation:
isnt it just finding a right angle?
Answer:
E(F)=200
V(F)=100
Step-by-step explanation:
(a) Let F be the amount he spends on falafel sandwiches over the next 400 days. Find E[F] and V(F).
If we analized his expenses in falafel sandwiches, we know he buys a $1 sandwich with aprobability of 50%.
If we call the random variable D the daily expense in falafel sandwiches, it is a Bernoulli variable with p=0.50.
If F is the sum of the daily expenses D during the 400 days, then we can say it is a binomial variable with p=0.5 and n=400.
Then we can calculate the expected value of F as:
The variance of F is then
C. Would be the answer Milana