quiz_5.docx

SHORT ANSWER with Work Shown. Record your answers and work.

Problem Number

Solution

1

Given the function f, prove that f is one-to-one using the definition of a one-to-one function.

f(x) = 4 2x

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2

Graph the equation by substituting and plotting points. Then reflect the graph across the line y = x to obtain the graph of its inverse.

y = x² + 1

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3

For the function f, use composition of functions to show that is as given.

f(x) = (x) = 4x 5

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4

Find each of the following, to four decimal places, using a calculator.

a) ( ²

b) log 0.082

c) ln 0

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5

a) Sketch the graph and use the graph to determine whether the function is one-to-one.

b) b) If the function is one-to-one, find a formula for the inverse.

f(x) = 7 x

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6

Convert to an exponential equation.

a) t = 7

b) ln 0.38 = 0.9676

c) Q = k

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7

Find each of the following. Do not use a calculator.

a)

b) ln e

c) log 1

d) log

e)

f) 4

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8

Convert to a logarithmic equation.

a)

b)

c)

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9

Graph.

f(x) = ln x

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10

The number of foreign nationals who came to the United States to marry an American using a “fiancée Visa” has grown exponentially in recent years. The total number of fiancée visas is given by the function

f(x) = 5728.98 ,

Where x is the number of years since 1990 (Source: US Department of Homeland Security).

a) Find the total number of Visas in 2006.

b) Find the total number of Visas in 2009.

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11

The value of a stock is given by the function

V(t) = 58 ( 1 ) + 20 ,

Where V is the value of the stock after time t, in months. Find V (1), V (2), V (4), V (6), and V (12).

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12

The bacteria Escherichia Coli are commonly found in the human intestines. Suppose that 3,000 of the bacteria are present at time t = 0. Then under certain conditions, t minutes later, the number of bacteria present is

N (t) = 3000

How many bacteria will be present after 10 minutes? 20 minutes? 30 minutes? 40 minutes? And 60 minutes?

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End of Quiz Five