Ineed with these. they are hard.

Find the explicit from for the sequence :

This next question I edited a bit.  Your question just says find the four terms.  I'm assuming they meant the first four. I also changed the c to an .

Find the first four terms of the sequence given by: :

a) 2,1,0.-3

You might want to read that second question again because there is errors in the question or things that don't really make sense.  I made my own interpretation of the problem based on my own mathematical experience.

Step-by-step explanation:

So your first question actually says that you can find a term by taking that term's previous term and adding 4.

So more terms of the sequence starting at first term 6 is:

6,10,14,18,....

This is an arithmetic sequence.  When thinking of arithmetic sequences you should just really by thinking about equations of lines.

Let's say we have this table for (x,y):

x  |   y

----------

1      6

2    10

3     14

4     18

So we already know the slope which is the common difference of an arithmetic sequence.

We also know point slope form of a line is where m is the slope and is a point on the line.  You can use any point on the line. I'm going to use the first point (1,6) with my slope=4.

   :I added 6 on both sides here.

    :I distribute here.

       :This is what I get after combining like terms.

So and so you have:

---------------------------------------------------------------------------------------

The first four terms of this sequence will be given by:

so it is between choice a, c, and d.

To find replace n with 2:

So we have to go another further the only one that has first two terms 2,1 is choice a.