Answer:
Step-by-step explanation:
Because of the nature of the information we are given, we have no choice but to use the equation

and solve for a.
We know by the info that the vertex is (0, 84). We also know that if the vertex is at the origin, and that the base is 42 feet wide, it spans 21 feet to the right of the origin and 21 feet to the left of the origin. That means that we have 2 coordinates from which we need to pick one for our x and y in the equation. I don't like negatives, so I am going to choose the coordinate (21, 0) as x and y. Because this parabola opens upside down, as archways of door openings do, our "a" value better come out algebraically as a negative. Let's see...From the vertex we have that h = 0 and k = 84. So filling in:
and simplifying a bit:
0 = 441a + 84 and
-84 = 441a so
Good, a is negative. Your equation is, then:

Use the trick x+ y+ z =0 and 6+8+z=0,...so z= -14
Answer:
Last answer, height is 150 ft
Step-by-step explanation:
from the graph, you can clearly see, when T=3, H=150
Which means The firework is at a height of 150 feet
Answer:
D. Compound interest accrues on the interest, as well as the
principal.
<span>First rewrite y - 2x<span> 2</span> = 8 x + 5 as</span>
y = 2x<span> 2</span><span> + 8 x + 5 </span>
Complete square and determine vertex.
y = 2(x<span> 2</span><span> + 4x + 4) - 8 + 5 </span>
= 2(x + 2)<span> 2</span><span> - 3 </span>
<span>vertex at (- 2 , - 3) </span>
If parabola is translated 3 units to the left and 2 units up its vertex is also translated 3 units to the right and 2 units up .
<span>vertex after translations is at: (-2 - 3 , - 3 + 2) = (-5 , -1)</span>