H, it's asking for the total amount of money spent. so you add.
No the following coordinates do not show a function because of the y-values. In the pairs that you have, (3,5) and (0,5) have the y-values of "5" that are repeating.
Hope this helps. I learned that in math.
Steps:
1) determine the domain
2) determine the extreme limits of the function
3) determine critical points (where the derivative is zero)
4) determine the intercepts with the axis
5) do a table
6) put the data on a system of coordinates
7) graph: join the points with the best smooth curve
Solution:
1) domain
The logarithmic function is defined for positive real numbers, then you need to state x - 3 > 0
=> x > 3 <-------- domain
2) extreme limits of the function
Limit log (x - 3) when x → ∞ = ∞
Limit log (x - 3) when x → 3+ = - ∞ => the line x = 3 is a vertical asymptote
3) critical points
dy / dx = 0 => 1 / x - 3 which is never true, so there are not critical points (not relative maxima or minima)
4) determine the intercepts with the axis
x-intercept: y = 0 => log (x - 3) = 0 => x - 3 = 1 => x = 4
y-intercept: The function never intercepts the y-axis because x cannot not be 0.
5) do a table
x y = log (x - 3)
limit x → 3+ - ∞
3.000000001 log (3.000000001 -3) = -9
3.0001 log (3.0001 - 3) = - 4
3.1 log (3.1 - 3) = - 1
4 log (4 - 3) = 0
13 log (13 - 3) = 1
103 log (103 - 3) = 10
lim x → ∞ ∞
Now, with all that information you can graph the function: put the data on the coordinate system and join the points with a smooth curve.
The area of a trapezoid is
A = (1/2) h (b1 + b2)
where
h is the height
b1 is length of base 1
b2 is the length of base 2
We are given with the area and assuming that the trapezoid is isosceles, the length of base 1 is
b1 = 4 ft
If the height of the trapezoid is 4.5 feet, it ensures that the shed will fit inside the trapezoid patch of land. Therefore, the height of the trapezoid is 4.5 feet.