Arithmetic and Geometric Calc

Arithmetic equation to find a_x

a_n= a₁ + (n-1)(d)

Arithmetic equations used to find the sum

S_n= n/2 (a₁ + a_n) or S_n= n/2 (2a₁+ (n-1)d)

To find the formula for an arithmetic sequence with two terms you do..

Set up the on top of each other and subtract to find d then plug into other equations from there

Geometric equation to find a_x

a_n=a₁ x r^n-1

How do you find a geometric mean

gm= Radical starting # x Ending #

To find the sum of a finite geometic sequence the equation is…

S_n= a₁(1 - rⁿ) / 1 - r

To find the sum of a infinite geometric series with a converging sum is…

S_n= a₁ / 1 - r

To find the sum of a infinite geometric series with a diverging sum is…

No sum

To find the specific term in an expension you use…

_nc_r x (a)^x x (b)^r

What is r in the term expansion?

term - 1

What is x in the term expansion?

n - r