Answer:
a) 72.25sec
b) 6.25secs
c) after 10.5secs and 2 secs
Step-by-step explanation:
Given the height reached by the rocket expressed as;
s(t)= -4t^2 + 50t - 84
At maximum height, the velocity of the rocket is zero i.e ds/dt = 0
ds/dt = -8t + 50
0 = -8t + 50
8t = 50
t = 50/8
t = 6.25secs
Hence it will reach the maximum height after 6.25secs
To get the maximum height, you will substitute t - 6.25s into the given expression
s(t)= -4t^2 + 50t - 84
s(6.25) = -4(6.25)^2 + 50(6.25) - 84
s(6.25) = -156.25 + 312.5 - 84
s(6.25) = 72.25feet
Hence the maximum height reached by the rocket is 72.25feet
The rocket will reach the ground when s(t) = 0
Substitute into the expression
s(t)= -4t^2 + 50t - 84
0 = -4t^2 + 50t - 84
4t^2 - 50t + 84 = 0
2t^2 - 25t + 42 = 0
2t^2 - 4t - 21t + 42 = 0
2t(t-2)-21(t-2) = 0
(2t - 21) (t - 2) = 0
2t - 21 = 0 and t - 2 = 0
2t = 21 and t = 2
t = 10.5 and 2
Hence the time the rocket will reach the ground are after 10.5secs and 2 secs
Answer:
6
Step-by-step explanation:
Step 1:
3 ( 2x - 5 ) - 4x + 8 = - 1
Step 2:
5x - 15 - 4x + 8 = - 1
Step 3:
x - 15 + 8 = - 1
Step 4:
x - 7 = - 1
Answer:
x = 6
Hope This Helps :)
Answer:
d = √85
Step-by-step explanation:
d^2 = (X2 - X1)^2 + (Y2 - Y1)^2
= (2 - 0)^2 + (6 + 3)^2
= 4 + 81
d = √85
Answer:
cot²x
Step-by-step explanation:
Using the identity
sin²x + cos²x = 1, then
1 - sin²x = cos²x
1 - cos²x = sin²x
Thus
= 
= cot²x
Answer:
All the coordinates are changed to
(x, y) ⇒ (2x, 2y)
Step-by-step explanation:
Given - A triangle is to be dilated with the origin as the center of dilation and with a scale factor of 2.
To find - Which answer choice correctly maps this dilation algebraically?
Proof -
Let ABC is a triangle where A, B, C are the vertices of the triangle respectively.
Now,
Let the coordinates be (x, y)
If a triangle is to be dilated with the origin as the center of dilation and with a scale factor of a , then the coordinated be changes as
(x, y) ⇒ (ax, ay)
Here given , a = 2
So, all the coordinates are changed to
(x, y) ⇒ (2x, 2y)
