Self Quiz Unit 4

Click    for True  and    for False. Use a calculator when necessary.

1) A certain population increases according to the model P(t) = 250e .47t
Use the model to determine the population when t = 5. Round your answer to the nearest integer.

         t = 2621

               

2) Evaluate when t = 15:     300e-.076t

            300e-.076t =    9.595

               

3) The following is the graph of y = 5-x - 1
      Window [-2, 2] by [-2, 2]

graph

               

4)  Write in logarithmic form: 43 = 64.

  log 43 = 64

            

5) The domain of f(x) = 1 + e x  is:

  (-00, 00)

            

 6)   The range of f(x) = 1 + e x is (-1, 1).

           

7)  Evaluate: log7 7.

  The answer is 1

           

8)   Students in an algebra class were given an exam and then tested monthly with an equivalent exam.
The average score for the class was given by the human memory model

f(t) = 85 - 16 log (t + 1), 0 < t < 12

where t is the time in months. What is the average score after 3 months?

     The average score is 75

           

9)   The domain of the function: f(x) = 3 + ln(x - 1).

           is    (-1, 00)

           

10)    Evaluate log 47 using the change of base formula.

 1.4037

           

11)    Written as the logarithm of a single quantity: log2(x - 2) + log2(x + 2) =

                log4(x2 - 4)

           

12)  

           

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Solve for x: 3x = 81.   x =  4

t =12

Solve for x: log x + log(x + 3) = 1.

x = 2

Use a graphing utility to find a logarithmic model, y = a + b ln x, through the points, (1, 2), (2, 2.7), (3, 3.1), (4, 3.4), (5, 3.6). Round to the nearest integer.

Answer:

y = 2 + ln x