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:
a + b = 5
Step-by-step explanation:
To solve this system of equations, we can use a strategy called elimination, which is when we get rid of a variable by adding/subtracting two equations.
Firstly, we want to make sure the absolute value of the coefficients that equal.
Lets eliminate b:
4a + 6b = 24
Multiply both sides by 2:
8a + 12b = 48
We also have:
6a - 12b = -6.
Now lets add that with
8a + 12b = 48
-> 6a + 8a + 12b - 12b = 48 -6
-> 14a = 42
-> a = 3
Now that we know a, lets plug it into one of our original equations:
4(3) + 6b = 24
12 + 6b = 24
6b = 12
b = 2
Finally, add the two values we found:
a+b = 2+3= 5
Considering that the grows at a constant rate we can form an equation where x = how many years after it was planted
and y = its height
Now we just need to find how many feet it grows each year. To do that we just need to compare its height from a certain age to another:
6 years after it was planted : 7 feet,
so x=6 and y = 7
9 years after it was planted: 16 feet
so x= 9 y=16
With thay we can conclude that in 3 years , the tree grew 9 feet. To discover how much the tree grow each year we just nee to divide 9 feet by 3 years which is 3 feet every year.
To write the equatopn now we just need to find the y-intercept which we can discover by setting x to 0:
If in 6 years after the tree was planted it is 7 feet long , we can discover how long it was when it was planted by subtracting 6 years of growth (The slope ) which is 3
7 - 6(years)×3(feet the tree grow each year)
7 - 18 = -11
The tree was -11 feet long when it was planted
which is our y-intercept
( I know it doesnt make sense , but if you apply to a graph it will make more sense )
Now we can make the equation
y = 3x -11
Answer:
Step-by-step explanation:
7x - 15 = 4x - 12
3x - 15 = -12
3x = 3
x = 1
y = 7(1) - 15
y = 7 - 15
y = -8
(1, -8)
Revenue, R = 130x
Profit, P = Revenue – Cost
P = R – C
P = 130x – 2950 + 6x + 0.1x^2
At P = 0
0 = -2950 + 136x +0.1x^2
X = 21.355, -1381.355
Therefore, manufacture greater than 21.355 items to make
profit.