Answer: 0 ≤ x ≤ 4.75
Step-by-step explanation: Domain is the range of possible x values that make sense in the equation. Since the x values are time, and there cannot be negative time, x must obviously be positive. And since y is height and height can't be negative, the domain of x ends at the x-intercept, the point at which y begins to become negative. So the domain of x is 0 is less than or equal to x which is less than or equal to about 4.75.
B. 20x and .8x because they have the same variable
Answer:
x=6
Step-by-step explanation:
x+3=9
x+3-3=9-3
x=6
If the center is at (0, 0) and the vertex is at (20, 0), then the distance, a, is the length from the center to the vertex, 20. The distance from the center to the focus is c. The distance from the center to the focus is 16, so c = 16. The formula we use to find the focus is

. We have our c value and our a value, so we will sub in those to find b.

and 256 = 400 - b^2. -b^2 = -144, so b = 12. There you go!
Answer:
- Maria–Ava: 15.7 feet
- Lucas–Maria: 10.1 feet
- angle at Maria: 50°
Step-by-step explanation:
The cosine and tangent functions are useful here. The relevant relations are ...
Cos = Adjacent/Hypotenuse
Tan = Opposite/Adjacent
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The distance from Maria to Ava (ma) is the hypotenuse of the triangle, so we have ...
cos(40°) = 12/ma
ma = 12/cos(40°) ≈ 12/0.76604 ≈ 15.7 . . . feet
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The distance from Lucas to Maria (ml) is the side opposite the given angle, so we have ...
tan(40°) = ml/12
ml = 12·tan(40°) ≈ 12·0.83910 ≈ 10.1 . . . feet
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The angle formed at Maria's position is the complement of the other acute angle in the right triangle:
M = 90° -40° = 50°
In summary, ...
- Maria–Ava: 15.7 feet
- Lucas–Maria: 10.1 feet
- angle at Maria: 50°