Given the rational function r(x) = (1-x)/(x-2) , explain carefully why as x→ 2^- , r(x)→ ∞
Problem: Given the rational function \[r(x)\] = \[\frac{1-x}{x-2}\] , explain carefully why as \[x\to {{2}^{-}}\] , \[r(x)\to \infty \] . Be sure to discuss signs and sizes of numbers in your explanation.
3. Fill out the following information about the polynomial \[p(x)\] = \[-2x{{(x+2)}^{3}}(x-4)\] .
- (1 Point) As \[x\to -\infty \] , \[p(x)\to \] .
- (1 Point) The y-intercept of \[p(x)\] has coordinates .
c) (1 Point) The zeroes of \[p(x)\] are .
d) (5 Points) Make a rough sketch of \[p(x)\] on the axes below. Don’t worry about the scaling in the y-axis but be very accurate. Be sure to label all points with their (x,y) coordinate s . Also label the behavior of \[p(x)\] near its zeroes using the terminology we learned in class.
4. A function \[f(x)\] undergoes the following transformations to become new function \[g(x)\] :
"Shifted left 3 units, then reflected about the y-axis, then shifted down 2 units."
-
(1 Point) Using function notation, express
\[g(x)\]
in terms of
\[f(x)\]
.
\[g(x)\] =
Suppose you are given the following additional information about \[f(x)\] :
\[f(x)\] is a one-to-one function Domain of \[f(x)\] : \[(-\infty ,2)\bigcup (2,\infty )\] Range of \[f(x)\] : \[(-\infty ,1]\] -
(2 Points) Using interval notation, what are the domain and range of
\[g(x)\]
?
Domain of \[g(x)\] : Range of \[g(x)\] : -
(1 Point) Using interval notation, what are the domain and range of
\[{{f}^{-1}}(x)\]
?
Domain of \[{{f}^{-1}}(x)\] : Range of \[{{f}^{-1}}(x)\] :
5. Solve the following equations, show ALL work for FULL credit. Give exact answers. Use natural or common logarithms only if necessary.-
(1 Point)
\[{{2}^{x}}=14\]
b) (1 Point) \[{{x}^{2}}=14\]
c) (1 Point) \[3{{(4)}^{t}}=24\]
-
(1 Point)
\[{{2}^{x}}=14\]
-
(1 Point) log8 x =
\[\frac{-5}{3}\]
e) (1 Point) \[{{e}^{-5m}}=6\]
f) (2 Points) \[300=50{{\left( 1+\frac{0.03}{4} \right)}^{4t}}\]
g) (4 Points) \[\log (x-2)+\log (x+1)=1\]
h) (2 Points) \[2=\frac{8}{3+{{10}^{x}}}\]
6. Find the domains of the following functions using interval notation.
Show all work to receive full credit.-
(2 Points)
\[y=\frac{x-4}{{{x}^{3}}+4x}\]
b) (2 Points) \[w(t)\] = \[\frac{1}{1-{{e}^{t}}}\]
c) (4 Points) \[f(x)\] = \[\ln ({{x}^{2}}-5x)\]
d) (4 Points) \[g(x)\] = \[\sqrt{\frac{3-x}{x+1}}\]
7. Solve the following formulas for the indicated variable.
a) (4 Points) \[\ln A=\ln D-rt\] for the variable A. There should be NO logarithms in your final answer!
b) (4 Points) Solve \[B=p{{t}^{2}}-qt\] for the variable t.
8. Fill out the following information about the rational function \[f(x)\] = \[\frac{4(x-1)}{{{(x+1)}^{2}}}\] .
a) (1 Point) \[f(x)\] has a horizontal asymptote of y = .
b) (1 Point) \[f(x)\] has a vertical asymptote of x = .
c) (1 Point) \[f(x)\] has a hole at x = .
d) (1 Point) The y-intercept of \[f(x)\] has coordinates.
-
(2 Points)
\[y=\frac{x-4}{{{x}^{3}}+4x}\]
- (1 Point) The x-intercept of \[f(x)\] has coordinates
f) (1 Point) As \[x\to \infty ,f(x)\to \] .
g) (1 Point) As \[x\to -{{1}^{+}},f(x)\to \] .
h) (1 Point) As \[x\to -{{1}^{-}},f(x)\to \] .
-
(1 Point) Use your graphing calculator to find the only local maximum on the graph. State its (x,y) coordinates to one decimal place.
local maximum at
j) (5 Points) Make a rough but accurate sketch of \[f(x)\] on the axes below. Be sure to label all points with their (x,y) coordinate s and all asymptotes with their equations .
9. If \[g(x)\] = \[\ln (x)\] , use the Laws of Logarithms to write the following expressions two different ways:- (1 Point) \[g(2a)\] = or
b) (1 Point) 2 \[g(a)\] = or
c) (1 Point) \[g(a+h)-g(a)\] = or
10. There is a corresponding Newton’s Law of Warming for cold objects with an initial temperature of \[{{T}_{0}}\] warming up in a room of constant temperature \[{{T}_{S}}\] . The model for the temperature \[T\] (in °F ) of the warming object as a function of time t in hours is given by \[T(t)\] = \[{{T}_{S}}-D_{0}^{{}}{{e}^{-kt}}\] , where \[{{D}_{0}}\] represents the same difference between the room temperature and the initial temperature of the object.
I take a 20°F turkey out of a freezer on an 80°F day to thaw on the kitchen counter. After an hour the turkey’s temperature reaches 25°F.
a) (5 Points) Find the exact values ( no decimals ) of \[{{T}_{S}}\] , \[{{D}_{0}}\] , and \[k\] for this model.
\[{{T}_{S}}\] =
\[{{D}_{0}}\] =
\[k\] =
b) (3 Points) Cookbooks suggest that to avoid food poisoning you should transfer the thawing bird to a refrigerator when it reaches 30°F. How many hours of thawing can I safely do on the counter? Give your answer to the nearest tenth of an hour.
EXTRA CREDIT: (3 Points) Suppose I put the turkey in a 40°F fridge when the cookbook suggested in part (b). How long must the turkey stay in the fridge for it to completely thaw (ie. reach a temperature of 32°F)? Give your answer to the nearest tenth of an hour.
HINT: the value k is constant for a turkey!
Deliverable: Word Document
