Answer:
21.4
Step-by-step explanation:
took the quiz
Answer:
S(t) = 4.725t + 478.25
S(t) = 4.725(42)+478.25
S(t) = 676.7
Step-by-step explanation:
In the question, score is a function of time, that means time is the x-axis, while score is the y-axis.
Order the pairs to get:
(30,620) and (70, 809)
With these values, you use the the equation 
to get the slope m.
Use this equation and input any ordered pair to get the final function.
y-y1 = m(x-x1)
y-620 = 4.725x-141.75
y = 4.725x + 478.25
Replace x with t and y with S(t) to fit the x & y axis of the question.
Vertex: (-5,-2); parabola opens up;
General form of the equation for a vertical parabola opening up is:
y-k = a(x-h)^2; knowing that the vertex is at (-5,-2), we can write:
y+2 = a(x+5)^2. We need to find the value of the coefficient a.
From the graph we see that y is 10 when x is approx. -1 3/4 (or -7/4).
subst. these values into y+2 = a(x+5)^2, we get:
10 + 2 = a(-7/4 + 5)^2, or 12 = a(13/4)^2, or 1 = a(169/16).
Solving for a: a = 16/169 = 0.09, or approx 16/160, or 1/10. Unfortunately, this is not close to any of the four answer choices.
I thought it best to try again, and fortunately my second try was correct:
10+2 = a(13/4)^2, or (169/16)a. Thus, 12 = a(169/16)
12
Solving for a: a = ------------- = 1.14. The answer choice closest to this is 1.
169/16
Answer A is correct.
Answer:
10
Step-by-step explanation:
