Evaluate the sequence

Question

For the sequence A_n=3-5*(n-1),

the first term is?

the second term is?

the third term is? 

the fourth term is?

the fifth term is?

the common difference (d) is?

 

Answer 1

Don't be afraid of formulas. You just put something in, and something pops out.

 

n is the number of the term

For example, to get the first term, n is 1

To get the second term n is 2

 

1st term A₁=3-5*(1-1) = 3-5*0 = 3

2nd term A₂ = 3-5*(2-1) = 3-5*(1) = -2

3rd term A₃= 3-5*(3-1) = 3-5*2 = -7

The small number on A shows what number term.

 

To get the common difference subtract any term by the term before it.

For example, subtract the 3rd term by the 2nd term. OR subtract the 5th term by the 4th term.

It's called a common difference because the subtraction answer you get is the same, no matter which term you choose.

 

3rd term - 2nd term =

-7 - (-2) = -5