Unit 7 Self Test

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

1)  Find the first 5 terms of the sequence whose n th term is an = (-1)n(2n + 9). (Assume that n begins with 1.)

  -11, 13, -15, 17, -19,...

       

2)

         The sum is 38.

       

3)  Of the following  only (b) is an arithmetic sequence.

(a) 1, 3, 9, 27, 81,... (b) 1, 16, 36, 64, 100,...

(c) 2, 11, 20, 29, 38,... (d) 3, -5, 7, -9, 11,...

         

4)  The first 4 terms of the arithmetic sequence
with a1 = 3 and d = -3 are:

 3, 0, -3, -6,...
       

5)  The seating capacity of an auditorium with 25 rows of seats if there are 20 seats in the first row, 24 seats in the second row, 28 seats in the third row, and so on is  1500.  

        

6)  Of the following  (c) is a geometric sequence.

(a) 1, -3, 5, -7, 9,... (b) 6, 3, 0, -3, -6,...

(c) 2, 4, 8, 16, 32,... (d) -1, 0, -1, 0, -1,...

        

7)  The 28th term of the geometric sequence: 2, 2.4, 2.88, 3.456, 4.1472,...

 is 274.7411.

        

8) The sum of the first six terms of the geometric sequence with

a1 = 2 and a2 = -4 is 42.

      

9)  The sum of the infinite geometric sequence: 1, 0.9, 0.81, 0.729,... is 10.

        

10)

        Yes and  r = -2/3

       

© Joan Bookbinder 1999