In the first week of Pre-Calculus 11 we learned about Arithmetic Sequences and Series. We learned how to find the sum, a specific sequence number, and how to solve for the general rule for the sequence. I will be showing you how to do all of these in this blog post.

Sequence —> 13, 22, 31, 40, 49…

Formula —> tn = t1 + (n-1)d

Specific Sequence
t50 = ?

tn = t1 + (n-1)d

t50 = 13 + (50-1)7

t50 = 13 + (49)7

t50 = 13 + 441

t50 = 454

General Formula

tn = t1 + (n-1)d

tn = 13 + (n-1)9

tn = 13 + (9n)

Sum of 50 Terms
Formula —> Sn = \frac{n}{2} (t1 + tn)
S50 = ?

S50 = \frac{50}{2} (t1 + t50)

S50 = \frac{50}{2} (13 + 454)

S50 = 25(467)

S50 = 11,675