Question

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

Answer 1

recheck 1,3
I don't understand 2

Answer 2

do you know about sigma notation?