Answer:
18 minutes
Step-by-step explanation:
A = A₀ (½)^(t / T)
where A is the final amount,
A₀ is the initial amount,
t is the time,
and T is the half life.
A = 140 when t = 10. Solve for the half life:
140 = 700 (½)^(10 / T)
0.2 = ½^(10 / T)
log 0.2 = (10 / T) log 0.5
10 / T = 2.32
T = 4.31
When A = 40, t is:
40 = 700 (½)^(t / 4.31)
0.057 = ½^(t / 4.31)
log 0.057 = (t / 4.31) log 0.5
t / 4.31 = 4.13
t = 17.8
Rounded to the nearest whole number, it takes 18 minutes.
Answer: D (I think)
Step-by-step explanation:
Answer:
three sides measuring 4 ft, 8 ft, and 10 ft
Step-by-step explanation:
To choose which dimensions that can create more than one triangle, we consider the given values carefully and how possible it will be to construct.
The only dimensions given in the option that will be possible to create more than one triangle from it, is three sides measuring 4 ft, 8 ft, and 10 ft.
4 ft, 8 ft, and 10 ft are in simple multiple of 2
4 ft, 8 ft, and 10 ft = 2 (2 ft, 4 ft, and 5 ft ), with this we can construct two triangles with three sides measuring 2 ft, 4 ft, and 5 ft.
<h3>
Answer: c. 8(y-6) = (x-2)^2</h3>
Explanation:
The directrix is horizontal, so the axis of symmetry is vertical. We'll have an x^2 term. The vertical distance from y = 4 to y = 8 is 4 units. Cut this in half to get 2, which is the focal distance p = 2.
The point (2,4) is directly below (2,8), and the point is on the directrix. The midpoint between (2,4) and (2,8) is (2,6). This is the vertex.
(h,k) = (2,6)
4p(y-k) = (x-h)^2
4*2(y-6) = (x-2)^2
8(y-6) = (x-2)^2
