# algebra

posted by
**Marissa** on
.

1)Find a1 in a geometric series for which Sn=300,r=-3,and n=4

a.15

b.15/2

c.-15

d.1/15

answer=a

2)Find the sum of the infinite geometric series n=1 at the bottom of the sigma notation 20(-1/4)n-1 on the right side

a.25

b.80/3

c.16

d.does not exist

answer=c

3)Find the sum of the infinite geometric series :4+3+9/4+:...

a.16/7

b.16

c.-12

d.does not exist

answer=c

4)Write Find the third iterate x3 o f(x)=x^2-4 for an initial value of x0=2

a.-4

b.4

c.12

d.-12

answer=c

5) Which is NOT a counterexample to the formula 1^2+3^2+5^2+...+(2n-1)^2=n(2n+1)/3

a.n=3

b.n=2

c.n=1

d.n=4

answer=c