Answer:
14 pints of 20% juice
56 pints of 95% juice
Step-by-step explanation:
Let
x be pints of 20% pure fruit juice, thus
70 - x will be pints of 95% pure fruit juice
The equation, thus can be written as:
20%x + 95% (70-x) = 80% (70)
Solving for x:
And 70 - x would be 70 - 14 = 56
Thus,
14 pints of 20% juice is needed, and
56 pints of 95% juice is needed
9514 1404 393
Answer:
Step-by-step explanation:
I find it convenient to draw the graph first when looking for relative extrema.
The function can be differentiated to get ...
f'(x) = -3x^2 +9
This is zero when ...
-3x^2 +9 = 0
x^2 = 3
x = ±√3 . . . . . x-values of relative extrema
Then the extreme values are ...
f(±√3) = x(9 -x^2) = (±√3)(9 -3) = ±6√3
The lower extreme (minimum) corresponds to the lower value of x (-√3), so the extrema are ...
(x, y) = (-√3, -6√3) and (√3, 6√3)
__
Since the leading coefficient is negative and the degree is odd, the function is decreasing for values of x below the minimum and above the maximum. It is increasing for values of x between the minimum and the maximum.
decreasing: x < -√3, and √3 < x
increasing: -√3 < x < √3
