Week of January 4

Well since I have a couple practice exams from first hour, and one from fifth hour, and the exam review we did in class last week, I guess I'll do some questions from them.

Water is poured at a constant rate into a conical reservior. If the depth of the water, h, is graphed as a function of time, the graph is:

A) decreasing
B) constant
C) linear
D) concave up
E) concave down

You know the question is talking about the first derivate, because it says a 'constant rate'. From that, you can eliminate that the graph is: C) linear, D) concave up, and E) concave down. You then use logic to realize that if the width of the cone keeps getting bigger or smaller, the height would not be a constant, so the A) constant would be elimated. This would leave you with A) decreasing.


If F(3) = 8 and F '(3) = -4 then F(3.02) is approximately:

A) -8.08
B) 7.92
C) 7.98
D) 8.02
E) 8.03

You can use y-intercept form to solve this problem.
The problem gives you that x = 3, y = 8, and m = -4
So you plug it into the y-intercept form and get:
y - 8 = -4 (x - 3)
Equals: y - 8 = -4x + 12
So you then plug the x they want you to find, 3.02, into the problem and get that:
y = 7.92
So the answer is B) 7.92.


Ahh, well school is cancelled Monday, so I guess I will see you all on Tuesday!!!