Answer:
1)The rocket hit the ground at ![x = \frac{5}{4}](https://tex.z-dn.net/?f=x%20%3D%20%5Cfrac%7B5%7D%7B4%7D)
2)The maximum height of the rocket = 12.468 feet
Step-by-step explanation:
<u><em>Step(i):-</em></u>
Given equation
y = -2 x² + 5 x + 7 ...(i)
Differentiating equation (i) with respective to 'x' , we get
![\frac{dy}{dx} = -2( 2x) +5(1) = -4x +5](https://tex.z-dn.net/?f=%5Cfrac%7Bdy%7D%7Bdx%7D%20%3D%20-2%28%202x%29%20%2B5%281%29%20%3D%20%20-4x%20%2B5)
Equating zero
![\frac{dy}{dx} = 0](https://tex.z-dn.net/?f=%5Cfrac%7Bdy%7D%7Bdx%7D%20%3D%200)
⇒ -4 x +5 =0
⇒ -4 x = -5
⇒
<em> The rocket hit the ground at </em>
<em></em>
<u><em>Step(ii):</em></u>-
...(ii)
Again differentiating equation (ii) with respective to 'x' , we get
![\frac{d^{2} y}{dx^{2} } = - 4(1)](https://tex.z-dn.net/?f=%5Cfrac%7Bd%5E%7B2%7D%20y%7D%7Bdx%5E%7B2%7D%20%7D%20%20%3D%20-%204%281%29%20%3C0)
The maximum height at x = ![\frac{-5}{4}](https://tex.z-dn.net/?f=%5Cfrac%7B-5%7D%7B4%7D)
y = -2 x² + 5 x + 7
![y = -2 (\frac{5}{4})^{2} + 5 (\frac{5}{4} ) + 7](https://tex.z-dn.net/?f=y%20%3D%20-2%20%28%5Cfrac%7B5%7D%7B4%7D%29%5E%7B2%7D%20%20%2B%205%20%28%5Cfrac%7B5%7D%7B4%7D%20%29%20%20%2B%207)
![y = \frac{-2(25)+ 25 (16)+7(64)}{64}](https://tex.z-dn.net/?f=y%20%3D%20%5Cfrac%7B-2%2825%29%2B%2025%20%2816%29%2B7%2864%29%7D%7B64%7D)
![y = \frac{798}{64} = 12.468 feet](https://tex.z-dn.net/?f=y%20%3D%20%5Cfrac%7B798%7D%7B64%7D%20%3D%2012.468%20feet)
<em>The maximum height of the rocket = 12.468 feet</em>
Answer:
a.0.12
b. Dependent
Step-by-step explanation:
a. The two events mentioned here are " print book is purchases" and "customer using gift card". P(P)=0.6 and P(C)=0.2. we have to calculate the probability of print book selection for purchase and payment is made through gift card i.e. P(P∩C). P(P∩C)=P(P)*P(C)=0.6*0.2=0.12.
b. If P(A∩B)=P(A)*P(B), then the two events are independent. Here in the given situation two independent variables are "purchase of e-book" and "payment made using gift card"
P(E)=0.4
P(G)=0.2
P(E and G)=P(E∩G)=0.1
P(E)*P(G)=0.4*0.2=0.08 that is not equal to 0.1. So, the two events "e-book is purchased" and "Payment made by customer using gift card" are not independent.
Answer:
Nathan: 2x+30
Olivia: 4x+15
Step-by-step explanation:
x is the number of weeks
Nathans account is as follows
2x+30
(2 dollars a week plus the 30 dollars already there)
Olivia's account is as follows
4x+15
(4 dollars per week plus the 15 already in there)
£100 - £y would be left :D
5/6
Since it is given that it is small, only worry about the small coins.
There are 18 total small coins and 15 of them are gold so 15/18 is the probability or when simplified = 5/6