Answers:
- Vertex form: y = -2(x-1)^2 + 8
- Standard form: y = -2x^2 + 4x + 6
Pick whichever form you prefer.
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Explanation:
The vertex is the highest point in this case, which is located at (1,8).
In general, the vertex is (h,k). So we have h = 1 and k = 8.
One root of this parabola is (-1,0). So we'll plug x = -1 and y = 0 in as well. As an alternative, you can go for (x,y) = (3,0) instead.
Plug those four values mentioned into the equation below. Solve for 'a'.
y = a(x-h)^2 + k
0 = a(-1-1)^2+8
0 = a(-2)^2+8
0 = 4a+8
4a+8 = 0
4a = -8
a = -8/4
a = -2
The vertex form of this parabola is y = -2(x-1)^2+8
Expanding that out gets us the following
y = -2(x-1)^2+8
y = -2(x^2-2x+1)+8
y = -2x^2+4x-2+8
y = -2x^2+4x+6 .... equation in standard form
Your answer D. 8 is right; this is
64, which we know is 3 because 4^3 is 64.
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Hope this helps!
==jding713==
try the very last one might be wrong but...
Answer:
0.98 km/h
Step-by-step explanation:
Converting mi to km: 66*1.6 = 105.6 miles
Imani's average: 105.6 miles/ 90 min = 1.73 km/h
Abedi's average: 56 miles/ 75 min = 0.7466 ≈ 0.75 km/h
Difference: 1.73-0.75 = 0.98 km/h
