Hello,
y= x^3-4x²-3x+18=(x-3)²*(x+2)
y'=3x²-8x-3
y''=6x-8
1) Stationary points
Maximun: x=-1/3 ==>y=18,5185....
Minimum: x=3 ===>y=0 (double root)
2) x=4/3: point of inflection. (y''=0 and change sign)
The given data is
x f(x)
---- --------
12 0
20 800
30 1800
where
x = number of clients per month
f(x) = monthly revenue
A graph of the data is shown below.
Let the equation of the line be
y = mx + c
The x-intercept is 12, therefore
12m + c = 0 (1)
The line passes through (30, 1800) and (12,0). Therefore the slope is
m = 1800/(30-12) = 100 (2)
From (1), obtain
c = -12m = -12*100 = -1200
Therefore
y = 100x - 1200
Answer: D. f(x) = 100x - 1200
The expression inside the absolute value can be either positive or negative.
above, they solved for x in the positive expression. x/2 + 3 = 2
solve for x in the negative expression.
x/2 + 3 = -2
x/2 = -2 - 3
x/2 = -5
x = -10
The correct answer is he would be at 80 ft
3x+2x-13=47
5x-13=47
5x=60
x=12