Finding the first term

[albswb]

What is the first term of an arithmetic sequence with 100th term 25 and common difference 0.2?

I have no clue how to find this out...please help!

 

[pappus]

What is the first term of an arithmetic sequence with 100th term 25 and common difference 0.2?

I have no clue how to find this out...please help!

1. An arithmetic sequence has the general equation:

$\displaystyle a_n = a_0 + n \cdot d$

2. Plug in the known values and solve for $\displaystyle a_0$

 

[srmichael]

1. An arithmetic sequence has the general equation:

$\displaystyle a_n = a_0 + n \cdot d$

2. Plug in the known values and solve for $\displaystyle a_0$

Pappus, I spy an error in your formula above. It should be:

$\displaystyle \displaystyle a_n = a_1 + (n-1)\cdot d$

 

[Deleted member 4993]

Pappus, I spy an error in your formula above. It should be:

$\displaystyle \displaystyle a_n = a_0 + (n-1)\cdot d$

If the first term of the sequence is a₁ - then the equation should be:

$\displaystyle \displaystyle a_n = a_1 + (n-1)\cdot d$

 

[srmichael]

If the first term of the sequence is a₁ - then the equation should be:

$\displaystyle \displaystyle a_n = a_1 + (n-1)\cdot d$

Yup. I was too quick on the click (of the mouse). Thanks