The extreme values of the function f(x) = x - 4sqrt(x) occur at the values of x for which f'(x) = 0
f'(x) = 1 - 2/sqrt(x) = 0
sqrt(x) - 2 = 0
sqrt(x) = 2
x = 4
To check for minimum or maximum,
f''(x) = 1/(sqrt(x))^3 = 1/(sqrt(4))^3 = 1/(2^3) = 1/8 => the point is a minimum.
Therefore, the minimum value = f(4) = 4 - 4sqrt(4) = 4 - 4(2) = 4 - 8 = -4 and occurs at x = 4.
Answer:

which is the first option in the list of possible answers.
Step-by-step explanation:
Recall that the minimum of a parabola generated by a quadratic expression is at the vertex of the parabola, and the formula for the vertex of a quadratic of the general form:

is at 
For our case, where
we have:

And when x = 1, the value of "y" is:

Recall now that we can write the quadratic in what is called: "vertex form" using the coordinates
of the vertex as follows:

Then, for our case:

Then, for the quadratic equal to zero as requested in the problem, we have:

Given
gas prices are now $3.75 and it up 10% from 6 months ago.
Find out how much were gas prices 6 months ago.
To proof
gas prices now = $3.75
let the gas price 6 month ago = x
gas price now is rise up 10% from 6 months ago
First write 10% in simpler form

= 0.1
Now the equation becomes
0.1x + x = 3.75
1.1x = 3.75

x = 3.41 (approx)
Thus gas prices 6 months ago be $ 3.41 (approx )
Hence proved
How far would the cheetah have traveled in the first eight minutes? show how you arrived at your answer
Add all the minutes together, then divide by the number of students:
21+35+77+48+24+29+37+98+30+7 = 406 total minutes
10 students.
Average = 406 / 10 = 40.6 minutes per week.
The answer is A.