Written Homework 5
Math 1200
Instructions: Submit your work on Gradescope bySunday, September 22, 2023 at 11:59
pm. You must show all work.
1.The equation to the tangent line of a functiong(x) atx= 4 is given byy=−3x+ 10.
Findg(4) andg
′
(4).
2.C(t) represents the amount of caffeine (in mg) in the bloodstreamthours after a cup
of coffee has been consumed. Describe the physical meaning of the quantityC
′
(3).
Include units in your answer.
3.Find the equation of the tangent line to the functionh(x) =
1
x+ 3
at the point
1,
1
4
.
Use the limit definition of the derivative to compute any necessary derivatives.
1
4.Each limit below represents the slope of the tangent line to the graph of a function
y=f(x) at a point (a, f(a)). Determine the functionf(x) and the value ofa.
(a) lim
x→3
|2−x|−1
x−3
(b) lim
h→0
e
h
−1
h
5.
Shown below is a portion of the graph of the functionf(x), which has domain [−5,6].
−5−4−3−2−1123456
−5
−4
−3
−2
−1
1
2
3
4
5
y=f(x)
x
y
(a) Find all points wheref(x) is not continuous.
(b) Find all points wheref(x) is not differentiable.
2
6.Consider the below graph of a functionf(x).Note that the graph is linear on the
interval (3,5).
123456789
−2
−1
1
2
3
4
5
y=f(x)
x
y
(a) Compute lim
h→0
f(4 +h)−f(4)
h
.
(b) Order the following from least to greatest:
i. The slope of the tangent line atx= 1.5
ii. The slope of the secant line on the interval [5,7]
iii.f
′
(3)
iv. The average rate of change off(x) on the interval [1,4]
v. The instantaneous rate of change off(x) atx= 8.
3
7. Using the limit definition of the derivative, find a formula forf
′
(x) whenf(x) =
1
√
x
.
4