An applicable equation of a vertical parabola in vertex form is:
y-k = a(x-h)^2
Let x=2, y=4, h=-1 and k=-1, where (h,k) is the vertex. Then,
4-(-1) = a(2-[-1])^2, which becomes 5 = a(9). Therefore, a = 5/9, and the
equation of the parabola is
y+1 = (5/9)(x+1)
Step 1: Read and understand the problem statement.
You are given (time, depth) pairs of (20 s, 8 cm) and (40 s, 0 cm) and asked to write an equation that describes the relationship of depth (y) to time (x).
The rate of change is (0 cm -8 cm)/(40 s -20 s) = -8 cm/(20 s) = -2/5 cm/s. Then in point-slope form using the second point, the linear function rule is
y = (-2/5)(x -40) +0
You can expand this to
y = (-2/5)x +16
y = -0.4x +16 . . . . . . using a decimal number for the slope
_____
If the bathtubs in your "draining race" start with the same level, the one with the steepest slope (-0.5 cm/s) will win.
It would hafta be answer choice D
If your looking for square feet then your looking for the area.
A = L * H
A = 17 * 8
A = 136 sq ft <==
Answer:

Step-by-step explanation:
For this case we have the following expression:

We need to remember that the natural log and the exponentiation with the base the euler number e are inverse operations, and if we apply exponentiation on both sides of the equation we got this:

We have the identity operator for this 

And that would be our final answer for this case.